Interest on saving for children over 18 years old

Let’s say I have given gift money to my sons and they are over 18 years old. Would their interest income fall under their own personal allowance? Does it matter if they have no other income? Thank you very much

Hi
As over 18, any income they receive is taxed as their own. Any tax due depends on the amount received as they will be due personal allowances of £12570 is they are UK resident.