We have junior isa as well as junior sipp. I would find a comparison tool for both to get more information
My partner has a nsi savings account for my daughter
We went for a junior isa and then just looked around for the best interest rate and a convenient branch location toi, that may not matter to others but we get cheques to pay in for him at bday and Xmas so needed a branch reasonably near by. Coventry building society was good at the time so we went there but as others have said check Money Saving Expert to compare the latest rates. Not all banks do children's accounts, some of them only have accounts for teenagers and above so definitely look online before travelling anywhere to save a wasted trip to a bank!
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
We've got junior ISAs for our kids, but I'd recommend having a look at Money Saving Expert to help decide which type of account would suit your family’s needs best.