Could insufficient funds on your card be the reason my card is declined whilst trying to make it a payment method
could the reason my card is being declined from being made a payment method be due to insufficient funds?
iPhone 6s Plus
Yes. Apple may try a test charge to see if it is a good card.
iTunes Store & Mac App Store: About payment card authorization holds - https://support.apple.com/HT201292 ~$1 to verify card, later removed. Also for Apple Music trial - https://discussions.apple.com/message/29203952#29203952