For regular monthly contributions Halifax are good: Their Kid's Annual Saver allows you to put in between £10 and £100 (not £250) per month, and you get 4% pa (used to be 6%). On the account anniversary date it's all transferred to a Young Saver (currently paying 2.25% pa), and the cycle starts again.

Ditto nationwide. the (current) account my children have with them even has the retro paper bank book in the plastic wallet.

Halifax are very good - 4% for a £250/month regular saver and 2.25% saver account for upto £20,000. Also do JISA, which i think is about 4% if the parent has a halifax account

Nationwide is good. Alternatively MoneySavingExpert has options!

Does anyone know where I can open a child's bank account for an under 7 year old? I have a child trust fund set up, but I would like something that's accessible as well. We used to have a natwest piggy account when we were small and someone from the bank would come into our school every month when I was in first school ** and I'm sure there were other banks available**. I must have been under 7 when we opened it because I did manage to get all my piggies!

Or possibly it's not an option as they are trying to stop money laundering for Key Stage ones!
Thanks