Can an additional card holder transfer the balance to another card that has their name only?

Spint

I have a 28 month interest-free Sainsbury's credit card which will be ending this June.

My wife has just received the 18 month interest-free Santander credit card for the purpose of transferring the balance of the other card to this one.

I've never done a transfer balance before and due to my ignorance, I have been told by both companies that the name on each card must be same.

Therefore, I applied for my wife to be an additional card holder for the Sainsbury's account.

I am assuming that my wife can then transfer the balance onto her Santander card.

I phoned Sainsbury's who told me my wife can't do the transfer but I can now do it on her behalf.

I'm a bit confused with this because if it's my name they use then won't Santander refuse the transfer request, unless Sainsbury's do use her name but it is me that authorises it since she's not a joint card holder but just an additional one?

I'm just wondering if anyone has any experience with this or know for sure if my goal is attainable with what I have done?

If you're wondering, I did not apply for the Santander card myself because according to MSE's credit report, her application was more likely to succeed.

Thanks very much and hope you can help.

[Deleted User]

You can't do the transfer as the Santander card is not in your name.  And your wife can't do it as Santander reportedly don't do transfers from cards not in the account holders name.

Your wife needs to get a BT card which will allow a transfer from a different name (most of them) or you need to get your own BT card.