Who owns the code, the data and the report?

I watched someone ask a supplier: why don't I own the report? The supplier did not have a good answer. It has shaped how I write contracts ever since.

My position

You paid for it, you own it. The code, the data, the documentation, and anything I produced while thinking about your business. If you took it to another developer tomorrow, they would have everything they need and would not have to ring me.

That is not generosity, it is self-interest. A client who stays because leaving would be painful is not a happy client, and they tell people.

The bit that is genuinely more subtle

Somebody once asked me, about a different arrangement: why would you even want to own the IP for someone else's project? The honest reason suppliers do it is leverage. The defensible reason is reusable components — the generic scaffolding that is not specific to you and gets used across clients.

That distinction is fine, as long as it is written down. What is not fine is a contract vague enough that nobody knows which is which until there is a dispute.

What to check before signing anything

• Does ownership transfer on payment, or on completion, or never — and is that written in the agreement rather than the email thread?
• Are the repository and the infrastructure accounts in your name, or your supplier's?
• If you use a third-party developer, do they have a back-to-back agreement, so your rights actually reach the person who wrote the code?
• Can you get a full export of your data without your supplier's help?

That last one is the practical test. Ownership you cannot exercise without permission is not ownership.