Who actually owns your website?
Who owns the domain, the hosting, the code, and the content of your website, why the answer is often not you, and how to check before it becomes a problem.
A website is not one thing you own, it is four separate things that can each belong to different people: the domain name, the hosting account, the code or design files, and the content. You own each one only if it is registered or licensed to you, and it is entirely possible to have paid for a website in full and still own almost none of it. The way to find out is to check who is named on each of the four, which takes about fifteen minutes.
Most people never ask this question until they want to change agency, and by then the answer matters a great deal. Here is what each piece is, how to check it, and what to do if the answer is not what you expected.
The four things you might or might not own
The domain name. This is the address, and it is the single most important thing to control. Domains are registered to a person or company through a registrar, and whoever is listed as registrant controls it. If your designer registered it on their own account, they hold the address your customers type, your email runs through, and your search ranking is attached to.
The hosting. This is the server the site runs on. If the hosting account is in your designer's name, you cannot move, back up, or access the site without them, even if the code is technically yours.
The code and design files. Ownership here comes from your contract, not from having paid an invoice. In many jurisdictions, whoever creates a work holds the copyright by default unless it is assigned in writing. A contract that says nothing about ownership usually means the designer keeps it and you have a licence to use it.
The content. Your text, photos, and logo. Text you wrote is yours. Photography and stock images are often licensed, sometimes to the designer rather than to you, and sometimes only for a specific use. A logo designed for you may not be assigned to you unless the contract says so.
Why platform choice changes the question
On a fully proprietary platform, you own your content and your domain, but you do not own the site in any portable sense, because it cannot exist off that platform. This is a normal trade, ease of use in exchange for lock-in, and it is fine as long as you chose it knowingly.
An open platform or a custom build behaves differently. The code can move to any host, so ownership becomes a question of what your contract says and who holds the accounts, rather than a question the platform decides for you.
Neither is wrong. The problem is only ever discovering which one you are in after you needed the answer.
How to check, in fifteen minutes
Domain. Look up your domain in a public WHOIS search and see the registrant. Privacy protection may hide the details, in which case log in to the registrar yourself. If you cannot log in, you probably do not control it.
Hosting. Try to log in to the hosting account directly. If the only route in is asking your designer, the account is not yours.
Code and content. Read the contract, specifically for the words assignment, ownership, licence, or intellectual property. If none of them appear, assume the code is licensed to you rather than owned by you.
Analytics and other accounts. Check whether you are the owner of the Google Analytics property and Search Console, not just a user someone added. Owners can remove users. Users cannot remove owners.
What to do if you do not own it
Do not panic, and do not accuse anyone. Most of the time this is not sharp practice, it is a designer who set things up on their own accounts because it was quicker, and never thought about it again.
Ask, plainly and in writing, to be made the registrant of the domain and the owner of the hosting and analytics accounts. This is a normal request and a reasonable designer will do it without fuss. For code, ask for a written assignment of the work you paid for. If you are mid-relationship and everything is fine, this is a much easier conversation than it will be later.
If someone refuses outright, that is important information about who you are working with, and it is better to learn it while the relationship is calm than during a dispute.
How to avoid the problem next time
Register the domain yourself, before the project starts, on an account in your business name. It costs very little and it is the single most effective protection there is.
Open the hosting account in your own name and add your developer as a user. Ask for written ownership terms in the proposal rather than after the invoice. And keep your own copy of the content, the images, and the logo files in original format, because a site you own is not much use if the assets that fill it live only on someone else's laptop.
The short version
You can pay for a website in full and still not own it. Ownership is decided by whose name is on the domain, whose name is on the hosting, and what the contract says about the code, not by who paid. Check all four now, while nothing is wrong, because the moment you actually need the answer is always the worst moment to find out.
See also: Questions to ask before you hire a web designer, How to review a web design proposal, Should you self-host or use a managed service.