I am the account holder on my daughter phone, although it is registered an her address and she now pay the bill. There are two points:

1st - My daughter switched to a new plan last month which should mean her bill comes to £10.99 a month; however, a payment of £20.23 was taken on the 22nd July although she did not go over my plan. Though this payment was successful, when she tried to change my direct debit details on the 26th it said a new direct debit could not be set up unless she paid the overdue amount of £20.23. She didn’t realise at this point she had already paid for this month, so she paid the £20.23 manually. She received no confirmation of payment so thought something had gone wrong and paid it again. However, now when she goes to my payment history it says that £20.23 was taken on 22nd July, and two payments of £20.23 were taken on the 26th. So, she is unsure why her bill has come to almost twice the amount it should be and she doesn’t know why she had an overdue payment when it was taken from my bank account on the 22nd, and she believes she is owed £40.46 from the two manual payments she unnecessarily made. She has tried to sort this but as I am the account holder she has not been able.

2nd point – Can she be made the main account holder.