Apple Pay cash requires the same Apple ID for iMessage and iCloud - error fix

Just went through an hour of frustration with this message while trying to pay my rent. I tried signing in and out of iCloud and iMessage, turned Apple Cash on and off, nothing worked. I found another thread somewhere suggesting to delete the message thread causing the problem.

I tried this and it worked.

I think the problem was that I recently changed my Apple ID and the old messages on that thread were sent using the former Apple ID. It seems like it should all be linked but I've had trouble with Apple ID issues before so I should have thought of this.

I hope this helps someone!