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Pre-filing Search: A Dilemma for Cash-Tied Start-Ups?

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For inventors and applicants seeking to protect their groundbreaking inventions through patents, making the right decisions regarding a pre-filing patent search may significantly impact the outcome of their patent application.

The question involves weighing the value of conducting a pre-filing search otherwise known as a preliminary search or a novelty search versus opting for drafting and filing a patent application without conducting a pre-filing search.

In this article, we will explore the advantages and disadvantages of both approaches, with a focus on how patent applicants – particularly cash-tied start-ups – can make the most of their limited funds while securing their patent rights.

What is a pre-filing search?

A pre-filing search may help to identify prior art including patents, published patent applications, scientific literature and other information relevant to an invention. The search is typically performed using various systems and databases with search tools including patent databases, scientific journal publications and online search engines.

A pre-filing search is not substantial, unlike the official search report conducted and issued by a Patent Office. However, a pre-filing search can serve as a cost-effective starting point for inventors and applicants seeking to make informed decisions about whether or not to proceed with a patent application, refine their invention, or explore alternative strategies based on the pre-filing search results.

Therefore, a pre-filing search can be seen as an initial investigation to assess the patent landscape and determine the potential patentability of an invention in relation to the state of the art.

According to s.2(1)-(2) UKPA 1977:

  1. An invention shall be taken to be new if it does not form part of the state of the art.
  2. The state of the art in the case of an invention shall be taken to comprise all matter (whether a product, a process, information about either, or anything else) which has at any time before the priority date of that invention been made available to the public (whether in the United Kingdom or elsewhere) by written or oral description, by use or in any other way [1].

At Alphabet IP, we typically recommend undertaking a pre-filing search prior to preparing and filing a patent application to help our clients determine if there are any similar inventions to their own that may prevent them from obtaining a patent, or that may restrict the scope of protection available – this step is of course optional, but advisable.

Informed Decision-making:

By conducting a pre-filing search, applicants can gather essential information about existing patents or published patent applications that may impact the patentability of their own invention. This may empower them to make well-informed decisions about their patent strategy, boost confidence with regard to the patentability of their invention, or may even help with deciding not to pursue what was previously thought to be a ground-breaking invention.

A pre-filing search may also be useful for developing the invention further, prior to incurring the costs of drafting and filing a complete patent application.

Identifying Risks and Opportunities:

An IP landscape search can be useful even if you are not actively looking to file a patent application. For example, the results may help to identify risks as well as opportunities.

A freedom-to-operate search, also known as an infringement analysis or clearance search can help you to identify patents that are in force that your business activities may otherwise infringe on. This is however treated separately to a pre-filing search which his intended as a novelty search prior to drafting and filing your own patent application.


In order to conduct a pre-filing search, it is useful to first define your invention in a manner that provides keywords that can be searched.

One way to do this is to have a draft set of claims, so allocating some resources towards an initial draft set of claims can provide a good starting point. The draft claims can of course be modified freely as compared with claims that are filed as part of a patent application at the Patent Office.

Hence, a pre-filing search can provide the impetus to draft your claims in a manner that the invention can be searched, with the peace of mind and freedom of knowing that you can refine your claims based on the results of the pre-filing search, prior to actually filing your patent application at the Patent Office.

Identifying Prior Art:

Equipped with the results of a pre-filing search, you may be able to draft your patent application to a ‘higher standard’ taking into account the results of the search, which may or may not otherwise anticipate the novelty of your invention.

Alternatively, a pre-filing search may provide you with the confidence to know that your invention appears to be novel, at least based on the pre-filing search results. However, it is important to bear in mind that any pre-filing search is usually limited by keywords and the time spent searching which is correlated to the budget. Therefore, a pre-filing search may not consider all of the available prior art in a field.

A pre-filing search is intended to provide a proportionate, cost capped, insight into a relevant field. If a more extensive search is required, for example, because you are operating in a very active technological field, then it may be advisable to perform a more comprehensive search, which may incur further time and expense.

In some cases, the costs may outweigh the benefits, considering that a significant cost will be incurred when actually drafting and filing a patent application. In other cases, the cost of a pre-filing search is justifiable.

With regard to budgeting and financial constraints, it is also important to consider that during the substantial search by the Patent Office, if the Patent Examiner cites multiple references, then further costs will also be incurred in formulating a response which usually involves technical analysis of the cited prior art, claim amendments and/or arguments to overcome the Examiner’s objections.

For example, a cash-tied start-up may not want to spend a disproportionately high amount of their initial funds on a pre-filing search relative to the costs associated with drafting, filing and prosecuting a patent application. There may be a plan to retain a part of the budget for technical analysis and for responding to the substantive search and examination report that will be later issued by the Patent Office.

That said, a pre-filing search can be seen as an important step for producing a patent specification that is drafted to a high enough standard in terms of detail, as this is what will ultimately help during prosecution, particularly in overcoming the Examiner’s objections with arguments and/or amendments that are well supported by the patent specification. Hence, a trade-off exists and the question of whether or not to perform a pre-filing search is indeed an important one to ask.

The costs and benefits of a pre-filing search largely depend on the field of invention, the invention itself i.e., how well the invention is defined, keywords, budget and preferences of the inventor or applicant among other factors including the inherent novelty of the invention. Sometimes, an applicant may be able to narrow the search to include certain applicants, or time periods among other parameters.

Cost Savings and Knock-out Prior Art:

Drafting a comprehensive patent application can represent a substantial cost and you would want to make sure it is done properly so that there is more support for amendments and/or arguments when responding to the search and examination report from the Patent Office, which may include prior art citations that were not previously found in the pre-filing search.

In some cases, a pre-filing search may yield results that anticipate the novelty of an invention. This may save the applicant costs that may otherwise have been incurred in drafting and filing a comprehensive patent application that may ultimately be rejected by the Patent Office.

In other words, you may decide not to proceed with drafting your complete patent application upon realising the results of a pre-filing search.

Balancing Costs and Quality:

Consider an applicant with limited resources who chooses to forego a preliminary search and directly proceeds with drafting and filing a patent application, and a substantive search is issued. There is every likelihood that the Patent Examiner may cite prior art that defeats the novelty of the invention, and the prior art may have been readily found via a pre-filing search. The patent applicant cannot now amend the patent application in a way that adds new subject-matter as these contravenes s.76(1) UKPA 1977, which states that:

An application for a patent which;

  • a) is made in respect of matter disclosed in an earlier application, or in the specification of a patent which has been granted, and
  • b) discloses additional matter, that is, matter extending beyond that disclosed in the earlier application, as filed, or the application for the patent, as filed, may be filed under section 8(3), 12 or 37(4) above, or as mentioned in section 15(9) above, but shall not be allowed to proceed unless it is amended so as to exclude the additional matter [2].

In another scenario, an applicant may perform a comprehensive pre-filing search and the Patent Examiner may still cite different prior art that anticipates the novelty of their invention.

Therefore, an applicant should be aware that a pre-filing search may yield completely different results to what the Patent Examiner may find and a pre-filing search does not really provide any guarantees in relation to the novelty of the invention i.e., it is not a substantial search report.

The nature of a pre-filing search is that is cannot be relied on in the same way as a substantive search despite some of the benefits of a pre-filing search can provide.

Instead, a pre-filing search can be thought of as a useful way of finding out that your invention is not actually new, which although disappointing may save you costs in the long run or incentivise you to further develop your own invention; or a pre-filing search may be considered as a starting point to produce a higher quality patent specification equipped with knowledge of the state of the art that the pre-filing search has yielded, while this is limited by the time spent searching and thereby the costs associated with the search.

Technical Expertise & Confidence:

In some cases, the inventor may be a pioneer in their respective field and have an extensive knowledge of the state of the art. For example, consider a scenario where the applicant is an academic researcher that has spent years developing technologies and is fully aware of the scientific literature and state-of-the-art including patents and patent applications.

In the above example, it may well be that a pre-filing search is not seen by the inventor as a useful exercise given that they are the leaders in their field and already have the confidence in their technologies being novel and inventive.

Even in this case, however, a pre-filing search may be a prudent step that can provide significant benefits particularly due to the vast scale of the state of the art throughout time, and given that this comprises all matter (whether a product, a process, information about either, or anything else) which has at any time before the priority date of that invention been made available to the public (whether in the United Kingdom or elsewhere) by written or oral description, by use or in any other way [1].

An Opportunity for Refinement:

A pre-filing search is not conducted by the Patent Office against a patent application and is therefore not a substantial search. Instead, a pre-filing search can be seen as more of a preparatory tool i.e., in preparation for filing a patent application, meaning that as you are not yet committed to prosecuting a filed patent application, and you are still in a position where you can draft your patent application freely with the pre-filing search results in mind.

Hence, armed with insights from the search results, applicants may refine their patent application to address potential novelty objections and increase the chances of successful patent prosecution towards obtaining a granted patent.


One of the key advantages of a pre-filing search can be its affordability assuming it is specified to a budget, making it an attractive option for individuals with budget constraints. If the objective of the pre-filing search is to complement the drafting and filing of a patent application, then an applicant may specify a budget for a pre-filing search that is proportional in relation to drafting and filing a complete patent specification.

To do this, an applicant can typically instruct a specialist search provider with the number of hours to be spent on a pre-filing search, but should expect a proportional level of detail in the search results.

For example, let’s take an inventor with a groundbreaking idea for a new medical device – faced with limited funds, the inventor decides to invest in a pre-filing search. The search results reveal a few patents in related fields, prompting the inventor to modify the scope of the invention in detail. As a result, they can proceed with a more focused patent application that may stand a better chance of being granted.

Summarising The Challenge:

The quality of a pre-filing search is largely dependent on how well the invention, as a starting point, is defined, which provides the keywords on how the search may be conducted. However, a pre-filing search is typically limited to the time and quality of the search, which is driven by costs.

There may be a need to balance the costs incurred in performing the pre-filing search as compared with drafting and filing a patent application. For example, if a pre-filing search is requested with e.g., 40 hours of searching, then this may actually cost more than drafting and filing a simple initial ‘priority application’ for the purposes of obtaining a filing date and a substantive search from the Patent Office, the latter may be more cost-effective.

In this latter case, the applicant may be faced with a further dilemma that if they wish to prosecute the priority application, they may in fact be prosecuting a patent application that was never drafted to a high enough standard in the first place or at least the applicant may have preferred to prosecute a more detailed patent specification.

It is not uncommon for applicants to intentionally file a priority application purely for the purposes of obtaining a filing date and a substantive search from the Patent Office before electing to withdraw the application; or in another case, to claim priority and file a subsequent application e.g., an international application, before the end of the 12-month priority term of the initial application expires.

It is important to bear in mind that any new subject-matter in the subsequent application would not benefit from the priority date of the initial application but would have an effective priority date of the subsequent application.


In summary, a pre-filing search can be seen as an essential step in the patenting process. It may help inventors and applicants understand the potential novelty of their invention and make well-informed choices to maximise the chances of obtaining strong patent protection for their inventions.

A pre-filing search can offer a cost-effective option for inventors and applicants to gain initial insights into the state of the art related to their invention. Although not mandatory, a pre-filing search may prove to be a prudent step that can provide significant benefits.

An important lesson to draw may be that to strike the right balance between the cost of the pre-filing search i.e., number of hours spent, against the overall cost of drafting the patent specification i.e., quality and detail. In theory, a pre-filing search may at least be expected to provide the applicant with some confidence in their patent strategy – this may include proceeding to draft and file a patent application; not pursuing a patent application at all; or refining the invention prior to drafting and filing a patent application among other possible outcomes.


At Alphabet IP, the cost of arranging a basic pre-filing search is typically around £800 plus VAT for a relatively simple invention. For this we use an external search company that undertakes keyword searching of title, abstract, and full text in and outside the best patent classes across all territories, in Patbase, Questel Orbit, Thomson Innovation and ESPACENET and other databases of published patent applications.

We recommend that you budget around £500 to £1500 plus VAT for technical analysis work if required. Of course, if there is a lot of prior art or the documents are long and/or complex the cost of both the pre-filing search and the analysis may be higher.

If you decide not to instruct us to arrange a pre-filing search before proceeding with drafting and filing your patent application, we typically recommend that you undertake searches of your own using publicly available search engines, such as ESPACENET and Google Patents, in order to get an initial insight into the prior art:

We have also provided links to these databases as well as other resources which you may find useful on our website [3].

The European Patent Office (EPO) has also provided a useful article with guidance on how you may perform your own search [4].

[1] The Patents Act 1977 (as amended) – Section 2: Novelty –

[2] The Patents Act 1977 (as amended) – Section 76: Amendment of applications and patents not to include added matter –

[3] Alphabet Intellectual Property Ltd – Resources –

[4] European Patent Office – Prior Art Searching –

To find out more about patents and intellectual property, or if you have any questions or would like to get in touch, please feel free to email us at