Are fees on balance transfer cards halal?

We are comfortable with paying those fees and view them as administrative fees as opposed to interest. Interest is usually significantly more than the fees they charge so there is a reason for the distinction between fees and interest.

However if there is not distinction and the contract is is just window-dressing a straightforward loan agreement then it wouldn’t be. We have no reason to suppose the majority of balance transfer credit cards are doing this, so would be comfortable with them unless proven otherwise.