Is this possible?

This may sound absurd, but was thinking about it today and want to know if it's possible. I have not yet had a credit card or a mortgage of any kind. But say if I had an IP and a credit card from a different lender. Is it possible to make a payment from the credit card into an offset account attached to the IP to reduce interest. When the interest free period ends for the credit card, you could simply replace the money back onto the credit card?? Or am I missing something entirely, sorry for the stupid question..

Yes, you are missing something. The card payment is treated as a cash advance attracting interest & cash adv. fees from day 1 - no interest free period.
And no question is too stupid. The only person that is stupid is the person that doesn't ask the question.;)

Regards JO