Only you can pay into your AJ Bell account, unless your account is a SIPP or you're the registered contact for a Junior Stocks and shares ISA.
For a SIPP, your employer can also pay into your account. You can find out how to set this up on our employer contributions page of the website.
Anyone can make a payment into a Junior ISA that you're the registered contact for. Find out how someone else can pay into a Junior ISA via the website.