Recently in the UK, the term free spins changed into extra spins due to advertising restrictions. Some casinos might even use some other terms like bonus spins for example. However, whether it is extra spins or bonus spins they all mean the same thing as free spins. And no deposit free spins/extra spins are given to UK players in the same way: after the registration is completed.
In the UK the registration process is nowadays longer than before and in other countries because the verification process is now part of the registration process as well. Previously the verification was only required when players wanted to withdraw money. All users must now have their account verified before free spins are given or they can make a deposit. In other words, casinos need to verify a player’s name, age, and address at the very least before they can start gambling. The aim of this new rule is not to annoy players but to make gambling safer. Also, it means you no longer have to wait to be verified before withdrawing your winnings – which was a common problem before (UK Gambling Commission).