Who owns the code when an agency builds your app?

Under UK law, the agency or freelancer who writes your app owns the copyright in its code, not you, even though you paid for it. Ownership only moves to you if there is an assignment in writing, signed by the developer. Without one you usually get, at best, a licence to use the app, which can make it hard to change agency, raise investment or sell the business later.

Who owns the code by default in the UK?

The person who writes the code owns it by default, and paying for it does not change that. The Copyright, Designs and Patents Act 1988 treats a computer program as a literary work, the same category as a book. Section 11 makes the author the first owner of the copyright.

There is one big exception. If the code is written by an employee in the course of their job, the employer owns it automatically. An agency is not your employee, and neither is a freelancer, so that exception does not help you.

The government's own guidance on ownership of copyright works puts it plainly: when you commission someone to create a work, the first legal owner is the person or organisation that created it, "and not you the commissioner", unless you agree otherwise in writing.

Many business owners find this surprising. It is the opposite of how buying almost anything else works, where paying the invoice means the thing is yours.

What does the law require to transfer ownership?

The law requires a written assignment signed by the person giving up the copyright. Section 90(3) of the 1988 Act says an assignment of copyright "is not effective unless it is in writing signed by or on behalf of the assignor".

So a friendly email saying "it is all yours" is not enough, and neither is a quote that says "full ownership on completion" if nobody signs a contract that carries it out. The assignment has to come from the agency, in writing, with their signature.

A good assignment clause names what is being transferred (the source code, designs, database structure and documentation), says when it transfers (often on final payment), and covers future copyright in work not yet written. That last point matters because most of the code does not exist yet when you sign.

What happens if the contract says nothing?

If the contract is silent, you are likely to have a licence to use the app rather than ownership of it. The GOV.UK guidance notes that courts may find an implied licence letting the commissioner use the work for the purpose it was made for, but that this "does not necessarily result in a transfer of ownership" and may be only a limited, non exclusive licence.

Non exclusive means the agency could, in principle, reuse or resell the same code to someone else, including a competitor. Limited means you may not be allowed to change it, hand it to another developer or use it for something new.

Courts can go further. In the Dr Martens logo case, Griggs v Evans, the Court of Appeal implied a term that the commissioned design should be assigned to the client. As Albright IP explains , courts are reluctant to infer assignments without a written agreement, and getting there took a court case. That is not a plan, it is a rescue.

Why ownership matters more than it seems

Ownership matters most at the moments you cannot predict when you sign. Three situations come up again and again.

• Changing agency. If the relationship ends, a new team needs the source code and the right to modify it. Without ownership or a broad licence, your old agency can say no, or name a price.
• Raising money or selling. Investors and buyers check who owns the intellectual property during due diligence. A gap in the chain of ownership can delay or reduce a deal, and fixing it later means asking the original developer to sign, on their terms.
• Building on it. A licence "to operate the app" may not cover turning it into a second product, licensing it to partners or adding it to another system.

None of this means agencies are acting in bad faith. Many simply use a standard template that keeps ownership by default. The point is to read it before you sign, not after you need it.

What should you check in the contract before you sign?

Check six things before you sign, and ask the agency to explain any you cannot find.

1. A clear assignment clause. It should assign copyright and other intellectual property in everything made for you, including future work, and the contract must be signed by the agency.
2. When ownership passes. On final payment is normal and fair. Make sure staged payments do not leave you owning nothing if the project stops halfway.
3. The agency's own building blocks. Most agencies reuse their own existing code, such as login systems or admin panels. It is reasonable for them to keep owning that. You then need a permanent, royalty free licence to use, change and transfer it as part of your app.
4. Open source. Almost every modern app uses free open source libraries. Ask for a list and their licences. Some licences come with conditions about sharing your own code, which matters if the app is your competitive edge.
5. Handover. Ownership on paper is not much use without the files. Ask for access to the code repository throughout the build, plus the app store accounts, domain names and hosting held in your company's name.
6. Subcontractors. If the agency uses freelancers, the agency needs assignments from them too. Otherwise the agency cannot pass on rights it never had.

This is not legal advice, and for a large project a solicitor's hour on the contract is money well spent. But knowing what to look for makes that conversation shorter and cheaper.

Does code written with AI tools change who owns it?

Code written with AI tools adds a layer of uncertainty, so the contract should deal with it directly. Today the UK is unusual in protecting "computer generated" works that have no human author. Section 9(3) gives authorship to the person who made the arrangements for the work to be created.

That may change. In its report on copyright and artificial intelligence , published on 18 March 2026, the government said it proposes that protection for wholly computer generated works "should be removed, while copyright should continue to protect works created with AI assistance". It has not set a date, and says it will keep monitoring the issue first.

For most commercial apps this distinction is narrower than it sounds. Developers use AI tools as assistants and then review, edit and assemble the result, which is AI assisted work by a human author. But the line between the two has not been defined, so it is sensible to have the contract say that everything delivered is assigned to you regardless of how it was produced.

The tools themselves usually stay out of the question. The GitHub Copilot FAQ , for example, says "GitHub does not claim ownership of a suggestion". It also notes that in rare cases, under 1 percent by GitHub's research, suggestions may match code the model was trained on, which is a licensing point for the open source list above.

Two questions worth asking any agency: which AI tools do you use, and do you keep the filters on that block suggestions matching public code? A clear answer is a good sign.

How KerenLabs handles ownership

When we build a web app or a mobile app , the scope and quote stage is where ownership gets settled, in writing, before any code is written. You should never have to discover who owns your product at the moment you most need it.

If you are scoping a project for next year and want a second opinion on a contract or a quote, book a free 15 minute call . We will tell you straight what to ask for.

Frequently asked questions

Does paying the invoice mean I own the app?

No. Under UK law payment alone does not transfer copyright in commissioned work. You need a written assignment signed by the developer, otherwise you are usually relying on an implied licence to use the app.

Can an assignment be added after the app is finished?

Yes. Copyright can be assigned at any time, so a missing clause can be fixed with a short signed document. The catch is that the developer has to agree, and they have far less reason to once the project is paid for.

Is a licence ever better than owning the code?

Sometimes. If an agency builds on its own platform that many clients share, a broad, permanent licence may be cheaper and perfectly adequate. Make sure it lets you modify the app, move it to another developer and transfer it if you sell the business.

Who owns the app store listing and accounts?

The developer accounts on Apple and Google belong to whoever opened them. Ask for the app to be published from accounts in your company's name, so the listing, its reviews and its users stay with you.