What is Affirm's Customer Service Number? Rui Kojima April 30, 2021 14:23 Updated To contact Affirm directly, you can contact their customer service team at 1-855-423-3729. Related articles How do returns work when I use Affirm to make a purchase? How do I return an order? How can I make a change to my order after it has been placed? Comments 0 comments Article is closed for comments.