Filing for a Patent Content from the guide to life, the universe and everything

Filing for a Patent

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Craig Doyle in a Sinclair C5 car.

IMPORTANT - If you have an invention that you might want to patent do not tell people about it. Read on and see why.

Dull (but Important) Small-print Stuff

This is not legal advice, nor is it a substitute for legal advice. This Entry is provided as a guide to help you get started, and hopefully help you to reduce your patent attorney's fees (remember: their time is your money). It is, however, by nature generalised and light-hearted. If you apply for a patent based solely on this Entry then you deserve everything you get in every sense, but the author does not deserve, and will not accept, any liability for trying to help1. You have been warned...


  • What is a patent?
  • Why should I want a patent?
  • When might I not want to apply for a patent?
  • What can I get a patent for?
  • What should my patent application say?
  • What do I do if I have already told someone about my invention?
  • What will happen to my patent application?
  • What will it cost me?
  • What do I do once my patent is granted?
  • Some patent related links.

What is a Patent?

A patent is a legal document, and basically represents a deal between the state and an inventor. It says:

I will let you exploit your invention for a while2 without competition if you tell everyone how you did it, so that they can develop your ideas.
It is a commercial tool and is designed to promote the development of new technical advances by providing some incentive for an inventor to disclose what he or she has come up with, rather than keeping it a secret.

Because of the nature of this 'bargain' that you are striking, it is essential that you have something new and don't give away your part of the deal for free. This is why you should not tell the public about your invention before you apply for the patent; if you do then you have nothing left to bargain with. If you start by not talking to anybody, you can't go far wrong. When you do need to talk to someone, make sure you have an agreement to say that what you discuss is confidential. That way, you have only made your invention available to those specific people and not to 'the public' in general.

A patent is intended to give an inventor the right to go to court and prevent others from commercially exploiting their invention. It does not give you the right to use the invention commercially yourself, (you may fall within a previous patent), and it does not prevent others from gaining patents for improvements within your invention3. This may sound odd, but it is very important and widely misunderstood. Indeed, there can be many 'layers' of patent protection which apply to a particular product. Consider the following simple example:

  1. Aaron Aardvark invents the hot-air balloon.
  2. He gains a patent for a 'balloon filled with lighter-than-air gas'.
  3. Brenda Bradshaw then invents a helium-filled balloon.
  4. Brenda gains a patent for a 'balloon filled with helium'.

Brenda can still patent her invention, assuming that it is considered a non-obvious improvement over Aaron's. She can't use helium balloons commercially however, because they are still 'balloons filled with lighter-than-air gas' and thus fall within Aaron's patent.

Aaron can stop Brenda from making any lighter-than-air balloons, but Brenda in turn can stop Aaron from making the improved helium balloons. As a result they will probably grant a licence to each other, or Aaron will make hot-air balloons and licence Brenda to make helium balloons in return for a payment (called a 'royalty'). In some cases (depending upon the law of the specific country) if there is a market for helium balloons and Aaron refuses to give Brenda a licence, then she can apply for a compulsory licence.

The 'bargain' nature of a patent also means that it is territorial; a 'deal' with the UK government cannot bind the US court to protecting you from competition in their country, for example. As a result, you will need to decide which countries are going to be significant for marketing or manufacturing your product. There are many techniques and several international conventions you can take advantage of to gain protection in the countries you need and can afford, but these strategies are well beyond the scope of this Entry.

If you have invented a new, more-efficient process for manufacturing Union Jacks, then UK protection will probably be all you need (with maybe India or China too if they are going to be mass-produced there). If you have really developed a universal cure for heart disease, however, stop reading now and pick up the phone book — you need 'P' for 'patent attorney'.

It is also of significance to appreciate what a patent is not: OK, so it's not a plate of chips, but it's also quite distinct from several other types of 'intellectual property' (IP) which protect various kinds of intellectual creation. As a brief summary, types of IP include:

  • Patents — protect a technical invention4, which is to say the functional features of a technical object or method.
  • Trademarks (particularly registered trademarks) — protect a 'mark' which distinguishes the goods or services of one provider from those of another. These are typically names (Coca-Cola™ or Ford™) or symbols (the Nike™ 'tick' or Apple™ logo), but can be other distinguishing characteristics (the Intel™ 'Plonk Plink Plonk Tink' sound).
  • Copyright — protects written or graphic creations including books, paintings and computer listings, as well other creative artworks such as sculpture and music. Copyright subsists in this Entry, for example.
  • Design Right (registered or not) — protects the aesthetic aspects of essentially functional objects — the 'look' of an iMac™ rather than its workings, or the handle of a teaspoon.

There are also additional, more obscure, types of IP in many countries, but this Entry relates solely to patents, which is to say to the protection of the functional aspects of a technical invention. Some of the resources linked to below, however, are also relevant to other types of IP, and most patent attorneys can either advise on all of the above rights, or work in firms which can provide that advice.

Why Should I Want a Patent?

Pretty much the only reason for filing a patent application is that you think you have made an invention that might have commercial value. Patents are expensive5 to acquire and you must have a viable chance of making some of this money back before it is worth applying for one.

Your invention does not have to be something that could be sold directly to the public (see below), but it does have to be commercially useful before you stand much chance of getting value from your investment in a patent. You can also use a patent to stop others from exploiting your invention, but again, unless this is in a commercial setting it's unlikely to be of much value.

The return you hope to receive from your patent or application can be from exploiting your invention yourself, by licensing others to exploit it, or by selling the patent/application. An individual inventor will rarely have the resources to exploit an invention themselves, but it has been done (for example the 'Dyson™' vacuum cleaner). More often an individual inventor will approach a company with their invention (for example the 'Workmate™' was invented by an individual).

Consider whether you could start manufacturing and selling your inventive items yourself. If it's a non-drip teapot then maybe you can. If it's a super-computer then maybe not. If you can't make a commercial go of your invention then you will need to approach a company who will either be your partner, or who will buy the invention and develop/market it themselves. When you come to approach them, researching the patent position can only strengthen your pitch to a prospective partner or buyer, particularly if you have a hopeful-looking application.

You will probably have guessed the next bit by now: make sure that whoever you pitch to signs a secrecy agreement before you tell them about your invention. They will most likely have a standard one, or you can probably find something suitable on the web. Many situations can be considered to have an 'implied agreement of confidentiality', but you really don't want to rely on that unless you have to.

When Might I Not Want to Apply For a Patent?

There are a number of times when you probably do not want to get a patent. The most common of these are:

  • So you can keep your invention secret.
  • You just want to stop someone else from patenting it.

Because of the nature of a patent as a bargain with the invention being published for all to see (see below), if you are pretty sure you can keep your invention secret then you may be better off without one. If the Coca-Cola™ company had patented their recipe, for example, we would now all be able to make Coca-Cola™ because they would have had to tell us how. The protection of a patent typically lasts 20 years, but in that case it would have run out ages ago.

You do not need a patent in order to do something with your invention. As we saw above, a patent simply lets you stop others (the competition) from doing it. As a result, if you simply want to be free to use your invention without someone else patenting it, you just have to make it known to the public. This is sometimes called a defensive publication.

In principle, all you need to do for a defensive publication is to write down what you have invented in a way that it can be reproduced, and then deposit at a public library, or somewhere where anyone can come in and view it (the Internet is also viable for this). In practice, however, if it is behind a sign saying 'Beware of the Leopard' or similar, the national patent offices examining future applications are not likely to know about it. That means that it will fall to you to monitor your competitors' applications and tell the patent offices about your publication, which would be a pain. As a result, you are better off trying to get your invention published in a journal of some sort. There are also some websites which provide this sort of service and claim to be tied in to patent office databases. You will have to pay at least a small fee for this.

In some countries (including the UK for example), if you were already using an invention and can prove this, even if you did not make the invention known to the public, then a new patentee cannot stop you. You might, however, be limited to exactly what you have been doing without any scope for varying this, so be careful before you rely on this. As a first precaution, to show you have been quietly using your invention, you might therefore want to write out your invention and get the most respectable person you know to sign and date it as a witness. If you are also thinking of applying for a patent, remember to get them to sign a secrecy agreement first, just in case. If you don't know any respectable people, or you don't trust those that you do know, then you could try mailing it to yourself to get a date from the post-mark (remember not to open it!). This at least gives you some evidence of when you were using the invention.

What Can I Get a Patent For?

The exact criteria for patentability varies somewhat from country to country. In general however, the requirements stem from the nature of a patent as a bargain. Usually three criteria must be satisfied:

  1. It must be new
  2. It must be an invention (ie, non-obvious)
  3. It must have commercial applicability (in a very broad sense)

The exact interpretation of these also varies between countries but generally:

  1. To be new something must not have been made available to the public at any time, in any way before (even if you didn't know about it or it was in a different language).

  2. To be an invention, it must have a technical element and thus methods of doing business, purely mathematic methods or un-extracted biological components are generally not patentable, and nor is software 'as such' (the USA is a little different here - see above). Your invention must also not be an obvious development from anything that has been known before (even if it was not obvious from what you knew).

    Methods of medical treatment are also often excluded from patentability for policy reasons (doctors should not be restrained from treating patients for fear of patent infringement). Pharmaceuticals as such and some types of uses are often allowable, however, as are technical developments implemented by software. Practice in these borderline areas varies very widely between countries and if you want to patent something like this, you really need a good patent attorney.

  3. To be commercially applicable it must be suitable for contributing to some type of industry. A classic example is that a condom or 'the pill' is industrially applicable as such, because it can be made in a factory. A new method of preventing conception, however, is not patentable because the actual method is carried out privately in your own home 6.

Your invention does not have to be a product that could be sold to the public (like a mousetrap), it could be something that could only be sold to a few companies (like a better brake disk for a Ferrari) or a method of doing something (like a process for coating stamps with glue). Improvements are OK as well, so if you have a better computer mouse, you can patent it even if 90% of it is the same as an old mouse, providing what you changed is advantageous and was not obvious.

What Should my Patent Application say?

There are two essential features of all patent applications, at least in significant countries, and again they follow from the nature of a patent as a bargain. These are:

  1. You must describe your invention so that someone in the relevant technical field could reproduce it without being inventive.
  2. You must state what it is that you are claiming protection for.

It is certainly not recommended that you write your own patent specification, because patent law is intricate and the procedures complex. It is worth having everything you will need available before approaching a specialist however, because this will save them time and you money. The following are points to think about:

What it is

You should know what it is you have invented. This sounds daft but it is actually very important, and the area where most technical specialists go wrong. The chances are that if you have made a new type of telescope, then the thing you have actually invented is not the telescope but a new method of gathering or focusing light, or a method of enlarging an image or similar.

This sounds like a pedantic difference (patent lawyers are professional pedants, but this tends to be by necessity rather than nature), but is critical to what you are going to claim protection for. If someone else comes along and makes a market-leading CCTV system using your same method and you get no credit in spite of your patent, you are going to be pretty upset.

The thing that you can hold in your hand is often (but not always) simply one embodiment of what you have actually discovered, and so you need to think of other applications for your 'invention'. Remember that your patent is a commercial tool, so look for other commercial applications of your idea.

Can it be Changed?

It is also important to think how your invention could be changed and still work. This again sounds odd, and indeed you may have spent a long time working out exactly how to achieve tip-top performance, but it is worth thinking about. If you say that a particular component is flat, or is present at a concentration of 1% by weight, is that really what you mean? Would it work if it was bowed a little, or would anything between 0.001% and 5% be OK?

You have to remember that if you are going to create a product with a significant market, someone will try to make a similar product that falls just outside your patent, so you should aim to cover all aspects of the invention that will function sufficiently well to be saleable. Your competitor's product may have 5% poorer performance, but if they haven't paid your development costs (after copying you), maybe they can afford to sell at half the price you will be asking. Your patent application will end with a set of 'claims' which define the scope of protection you are requesting. If nothing else, it would be advisable to have these written by someone who knows what they are doing.


You should also appreciate that what is written in your application may be all that you have to work with during the process of having the application granted. As a result, if you need to amend your case because the patent office finds some previous work you were not aware of, then you need 'basis' for your amendment. In practice, this means that whenever you might say, for example: 5 – 10 cm, what you will actually write is more like 1 – 30 cm, preferably 5 – 10 cm, more preferably 7 – 8 cm. This makes for very boring reading, but allows you to claim protection for as wide an area around your invention as the technical field allows. As a result, for every feature of your invention, think about what is best, what would work and what is likely to work. Put all of these in your application as 'fallbacks'.

Figures and Examples

Remember that you will need to describe your invention in a way that will allow someone 'skilled in the art' to reproduce it without undue burden. You will therefore need to describe the invention, and how it is made, used and applied. You should provide figures and examples of how the invention is made to work if they are appropriate. Your description needs to allow for the invention to be carried out over essentially the whole scope that you claim for your exclusive right, so consider this point with the previous one; how will you demonstrate the invention over a scope that will provide commercially valuable protection?

Technical Differences

It is also worth getting together all the information you can on similar items and looking at the technical difference between yours and theirs. Patent offices will conduct a search on your application in most countries, but if you already know what is out there, it is easier to emphasise the new points of your invention.

Remember that your invention has to be new and non-obvious for you to get a patent, so before you pay a fortune to have an application drafted, you could do some preliminary searches for previously patented inventions. Good places to look are:

  1. Espacenet
  2. USPTO patent search
  3. WIPO patent search

Professional Advice

Consider getting professional advice. If you needed to read this to tell you about patent applications, then you will probably need some help in preparing yours. Many firms will offer a free initial consultancy at which they will advise you as to whether they think your invention has the potential to be patentable. Why not use this free advice? In the UK the Chartered Institute of Patent Attorneys (CIPA) also runs so-called 'clinics' where inventors can get free advice from patent attorneys on a voluntary basis. This is primarily in London, but it might be worth the trip.

Research Patent Drafting

Finally, if you really do have to write your own application, or even if you are going to write a first draft to save your patent attorney some time (and your money), make sure you read some existing applications to see how they are written and laid out. US applications are quite good to look at, because they have section-headings, which give you a clue as to how to lay the document out. Also look at some European cases if you are applying outside of the US, because basis for 'fallbacks' is much more important in Europe, where the rules are very strict.

What do I do if I Have Already Told Someone About My Invention?

The first thing to remember is, of course, 'Don't Panic'. There are many ways and reasons why your disclosure may not stop your invention being considered new, but you do have to be careful. If you think there is an issue, take professional advice if you can.

If you are only interested in a patent in the US, (or maybe certain other countries like Chile and Saudi Arabia), then providing you made your invention public less than a year prior, you are fine. These countries have a so-called 'grace period' in which an inventor can publish and still claim a patent. You have to be careful relying on this however, because you really are burning your boats in places like Europe which have no grace-period. It doesn't matter if you are from the US or not: if you publish before you file, you are stuffed in most countries. Rely on grace periods only if you have to.

If your 'disclosure' is only to one specific party, then make sure that they are treating it as confidential. Get a confidentiality agreement signed, and make sure they haven't told anyone else. If possible include a clause in your agreement saying that this is simply formalising the implied confidentiality which existed since you approached them. Sneaky but necessary.

If you told someone about your invention in confidence and they subsequently made the invention public, then all may not be lost. Most countries allow the true inventor to file an application after (usually up to six months) an 'abusive' disclosure like this, but again, this is a time to consult someone who knows what they are doing.

If it turns out that you have made a public disclosure and your invention can't be patented, that does of course mean that other people can't get their own patents. You could go ahead and make the product anyway — you would simply have to compete with people copying your invention. Under no circumstances should you indicate that you have a patent when you don't — this is a criminal offence in many countries.

Next time you make an invention, consider a patent before you tell anyone.

What Will Happen to my Patent Application?

So, you have created an invention, and with appropriate help you have filed patent applications in appropriate countries. What now?

Well, not much initially. The first thing to realise is that it is all a pretty slow process. There is an initial 'priority' year, during which you can develop your invention, refine your application, and finalise your international filing strategy, all of which are way beyond the scope of this Entry. Six months later (18 months from your first application date) your application will be published.

Bear in mind that publication will happen even if your invention is not ultimately granted a patent, so patenting is a risk — you could lose your secrecy and still not get patent protection. The up-side of publication, however, is that after publication you may have protection against others using your invention, providing that the patent both publishes and ultimately grants in a form that covers their use, and could be expected to grant covering this. This is the reason you will often see 'Pat Pending' marked on items — the inventor has applied for a patent and is alerting you to this 'provisional' protection7.

Around the time of publication (usually a little before, depending upon the country), your application will be searched by the Patent Office and you will receive a Search Report8. The Search Report tells you what the Patent Office Examiner has found when he/she searched for previously published inventions in your technical area. It is worth reading this carefully, especially if your application has not yet been published. If the search report shows an earlier document which discloses the whole of your invention then it will not be considered novel, and thus your application for a patent will not be granted (remember: you must have a new invention as your part of the patent bargain). In this case, you may want to withdraw your application so that it doesn't publish and draw attention to an invention for which you now know you are never going to receive a patent9.

After search and publication, and possibly after you pay a further fee, your application will be examined. During this process, an Examiner will write a report, typically saying that your application cannot be granted because it covers something that is not new, is obvious, is not an invention, and so forth (see above). You will be set a deadline to respond, and you will then need to submit arguments and usually amendments to the claims (in writing) to overcome these objections. Again, this is a task best undertaken by a professional, but, at least in the UK, the Patent Office is sympathetic to lone inventors, and the Examiners will generally give you what help they can. You could try calling them to discuss the case — the worst they can say is No10. Try to make sure you meet whatever deadline they set (some are extendable, but ask someone if you're not certain which are, and what you need to do), because ignoring it is a great way to lose your investment irretrievably.

What Will it Cost me?

Okay: you've made your invention and resisted the temptation to tell the world about it. You've decided that you can't keep it a trade secret, found a viable market for it and turned up no killer earlier material when you searched the Patent Office databases. Perhaps a patent application really is what you need, but the million dollar question is: can I afford it?

Of course it's tempting to say that if you have to ask then you can't afford it, but that need not be true. What is true, however, is that you can spend any amount of money on patents11. There are certain minimum costs, and even these can be quite significant. Where you can really spend your money, however, is by submitting applications in a large number of countries, or by running up many hours of legal advice time. The more you can do yourself the less the costs will mount, but then the greater the chance that you will be wasting your time and money. DIY is higher risk but for lower stakes. Only you can make the call as to which method is for you, but the following table gives some indication of costs at various stages.

To help compensate for inflationary effects, the table is presented as a week's worth of 'real' income (take-home pay plus benefits etc.) for the mid-quintile UK household from the Office of National Statistics. This has been taken as the standard unit12. A unit roughly equates to the cost of two hours of professional time from your patent attorney.

The approximate costs of the various stages are shown below assuming a fairly short, technically straightforward and inventive case requiring only one examination report before grant. The UK Patent Office, now called the UK Intellectual Property Office, and the European Patent Office (EPO) have been used as examples, since application at the former is relatively cheap and at the latter is among the most expensive. This is because filing at the EPO allows a single application to be validated in many13 European countries. Costs at the UK IPO on the other hand are relatively low at the application stage, because the UK IPO subsidises search and examination from the renewal fees paid once the patent is granted. For the purposes of illustration, it will be assumed that the patent granted from the EPO is then validated in eight countries (the UK, France, Germany, Ireland, Italy, The Netherlands, Spain and Switzerland).

StageUK Official Fee EPO Official FeeAttorney's Fee* UK TotalEPO Total
Drafting 5 5 5
Filing 0 0.2 0.5 0.5 0.7
Search 0.4 3 2 2.4 5
Examination 0.25 4.5 3 3.25 7.5
Grant 0 1.5 1 1 2.5
Validation N/A 18** 5 N/A 23**
Total Renewal Yrs 5-10 1.5 18** 0.5 2 18.5**
Total Renewal Yrs 11-15 2.7 30** 0.5 3.2 30.5**
Total Renewal Yrs 15-20 4.2 52** 0.5 4.7 52.5**
Totals9.05128.218 27.05146.2
*These are inherently much more variable and depend upon the complexity of the case.
**In eight countries as above, including fees to agents in those countries, which are hard to avoid.

As you see, it is possible to achieve the grant of a UK patent, for the cost of less than a week's average income, if you do everything yourself. Unfortunately, you are likely to need at least some help, and that could add three months' worth of your income. Much more in a complex case! If you want protection for eight countries through the EPO, then the application costs are much higher — around nine weeks' income, even before you have paid for validating the application in your chosen countries. It is, however, less than applying in all eight countries separately. On 1 May, 2008, the 'London Agreement' came into force. This reduced the costs of validation in many European countries. At the time of writing, 15 countries including France, Germany, the Netherlands and the UK have signed up to the London Agreement. More countries should follow.

After grant you will need to renew your patent each year in each country. For brevity this has been compressed into three groups, but even from that, you can see that the costs escalate. The idea is that if your patent is worth keeping, you must be making some money from it by the later years.

All in all, this gives an example range of around nine weeks' income for the lifetime of a DIY UK patent up to nearly three years' worth of income for a European patent in eight countries with professional help. Add more countries, or apply for a more complex or contentious invention, and these costs rise still further.

What do I do Once my Patent is Granted?

Assuming that all goes well, after you have responded to one or two examination reports you should receive a shiny new patent14. Great. Your work is all done now, right? Well, not quite.

The first thing to remember is that you have bought an expensive15 commercial tool. So use it! When you or your collaborators make this blockbuster product you've invented, make sure you write 'Patent No GB123456', or whatever, on it. This is actually very important because your damages from an infringing competitor may well depend on you showing that they should have known it was a patented invention.

Secondly, make sure that you tell the Patent Office (or your attorneys if you have them) when you move to your new state-of-the-art factory on 200 acres of landscaped parkland. A patent needs to be 'renewed' annually, which amounts to paying a(nother) fee. If they don't know where to reach you, you won't get the reminders.

Thirdly, keep an eye on what your competitors are up to. You are responsible for policing your own patent, the state won't do that for you, so make sure you have an idea whether anyone is infringing it. If you think they are then stop! There are lots of traps to fall into when enforcing your patent rights, and this Entry can't even begin to analyse them, so get some professional advice before you even approach anyone.

Of course, you will hardly need reminding: next time you make an invention, consider a patent before you tell anyone. Finally, when your company enters the FTSE 250 on the back of your phenomenally successful patented invention, remember footnote one!

Useful Links

1He does accept free samples, however, when your patented 'iPod™ killer' reaches number one in the Christmas gift charts!2Typically 20 years from application.3Indeed, since the idea is to promote further development, this is rather the point of the exercise from the state's point of view.4The US is different here, and allows patents for 'everything under the sun made by man'. If you want to patent something non-technical then you need expensive professional help, possibly in more than one sense.5Like you wouldn't believe!6Or someone else's maybe, or even in the back of your mate's Capri™, but not generally in public or on a commercial scale.7Provisional protection, although effective from publication, cannot be enforced until after grant of the patent.8Again, the US is different here, proceeding straight to examination with no separate search stage.9Patent Offices have databases of scientific literature which scientific researchers would kill for, so just because they find it, doesn't mean your competitors will.10Well, they probably know worse words than that, but they're not likely to use them.11If you are Bill Gates wanting to test this statement, contact the author for all the help you'll need!12About £400 in 2005.1334 at the last count and rising.14Still called a 'letters patent' in some countries, which is infinitely more stylish.15Like you still wouldn't believe.

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