We love the new child accounts after having tried many including GoHenry and Rooster from my old NatWest account.
You’ve done a great job and on the whole I have no complaints at all.
It is perfectly understandable and reasonable that the kids don’t have their own bank account number and sort code.
But I would assume there is one thing you could do to make the process a little more seamless than it is currently.
Each child account could have a unique child reference number.
If the parent account receives a payment with a reference that matches the child reference number, you could skip the step of the parent having to transfer the funds and it could automatically be deposited into the child account.
E.g if a payment is sent to 040004 with my account number and a reference of XYZ, if that reference matches my child reference, the payment is sent automatically to the child account, skipping the payment account entirely.
This way, grandparents can be given my account details and the child reference, and there’s no action on my part (or delay) to transfer the money to the child.