If you have a credit balance on your card (i.e. you’ve accidentally overpaid) every other card I have ever used shows a negative account balance.
As for your available balance it should still show at least your full credit limit in these circumstances
Seems Tandem’s systems have a bug in them/have not been programmed to take account of potential overpayments correctly.
Yes, you won’t start getting 0% until the 14 March statement is produced.
You could be right, as up until a couple of days ago, the C/C balance was showing as zero and the available balance showing as my credit limit PLUS any amount of overpayment left.
ie £1500 credit limit + £185 overpayment, £1685 available balance
Today it shows C/C balance of zero, but the available credit as £1464.77, exactly the £35.23 I spent at the garage short of the credit limit.
I know that the card was still at least £60 in credit before using it today.
UPDATE, looks like it was a bug.
It’s now showing the +ve balance again 
Also got the cancelled email yesterday
What was the “cancelled email”?
I also got a text.
The text said that they sent out a letter to inform about the changes (= blocking and closing the account). But with an incorrect date.
Well, this is the end then.
Has anyone any experience yet on getting refunds from a now-closed Tandem card? I am going to start get refunds for things booked months ago and obviously can’t spend the credit on the card, so just wondered how good they were at getting the money back to you?
I had an issue with them once (it was a while ago), around getting some money back. It took 3 weeks
for anyone else who took membership …interest rate on savings has dropped to 1.25
Higher than marcus
Contact them?
So I am confused what tandem is for now.
Membership is only open to the previous cashback card users. Anybody who cancelled, cannot reapply. Mamy have cancelled. New memberships are not offered. The have savings and basic card on offer, but both are niche and similar to other offerings out there.
From the website, there still needs to be a ‘Yet’ on the end of that sentence.
The waiting list is still live so I assume that the aim is still to open our Membership to the wider public.
Hm their FAQ are cryptic too
If I close my account can I re-apply at a later date?
No. Once the account has been closed, Tandem Membership will no longer be available but please bear in mind you do have until 9th March 2020 to make a decision.
https://help.tandem.co.uk/en/articles/3615880-tandem-membership-faqs
Not sure if “no longer be available” is universal, or only specifically to those who tried to quit tandem. Similar answers about the cashback credit card.
I think that was just for us ex-customers.
I suspect they planned to launch it more widely but have put it on hold due to COVID.
Just got an email from Tandem, they’re closing their Journey card in November and from the sound of it aren’t planning on offering credit cards anymore.
