There are reported problems with Tangerine-- which seem to be problems with the bank not with eBay.
I have had problems with Managed Payments and Simplii, although another ID had no trouble with the same account.
The usual advice is to try another bank. Annoying but it works.
Second, are you trying to attach to a chequing account? Savings accounts don't work.
Third, do all your names match exactly?
If your name is John Jacob Jingleheimer Smith, you cannot have
- a bank account as J J Jingleheimer Smith ,
- a Managed Payment account as John Jacob Jingleheimer Smith,
- and an eBay account as JJJ Smith.
And finally, stay away from the phone clerks.
The phone reps have a terrible reputation for getting you off the phone as soon as possible even if that means giving you the advice you want to hear instead of the advice you need to have.
The social media Chat accounts are covered by trained eBay employees with some authority.
And you get a transcript so you can compare what you heard with what you were told.
