What is Affirm's Customer Service Number? Rui Kojima November 13, 2023 20:15 Updated To contact Affirm directly, you can contact their customer service team at 1-855-423-3729. Related articles Does Affirm do a credit check and will it affect my credit score? How do returns work when I use Affirm to make a purchase? How do I make payments with Affirm? What is Affirm? How does the Affirm check out process work? Comments 0 comments Article is closed for comments.