Child turning 16 with savngs

My son is about to turn 16 in march and I have been putting money away into a Junior Easy Save with OneFamily previously engage mutual.


The account has about 4k in it and is about to be transferred over to him. I dont want this to happen as 4k for a teenager is not the best idea. He wants to buy a car at 17 so I am thinking of taking the money out while I still have control of the account and putting it into savings for him that he can get when he turns 17. I have looked at lots of options like ISAs or child savings accounts and I am looking for advice on what is best.


Santander do the 123 account where you can get a monthly interest of 3% AER on balances up to £2k.

TSB also do an under 19 account where you get a monthly interest of 2.5% AER on blances up to £2.5k


Am I best to get him to set up both accounts putting 2k in each or is it better to put it into an ISA bearing in mind that he needs to access the cash in one years time?


Thanks