This surprises people, so it is worth explaining properly.
WHAT HAPPENS WHEN YOU REGISTER
We pay the registry immediately and the domain is registered in your name for the period chosen. That fee is spent at the moment of registration and cannot be recovered by us, by any registrar, at any price.
The registration is a completed transaction with a third party, not a service we can stop delivering.
THIS IS UNIVERSAL
Every registrar operates this way, because every registry operates this way. It is not a policy we chose and not one we can make an exception to.
WHAT THIS MEANS FOR YOU
Check the spelling carefully before paying. Check the extension is the one you meant. Check the renewal price, not just the first-year price. If you are unsure whether you want the name, think first. It costs nothing to wait a day, and cannot be undone afterwards.
WHAT IS DIFFERENT
If a registration genuinely failed and no registry fee was incurred, that is refundable or creditable, because nothing was spent.
IF YOU REGISTERED THE WRONG NAME
You own it. You can let it lapse at the end of the term, or use it as a redirect to the correct domain, which costs nothing extra.