"Buy now, pay later" loans should not affect your credit score when you sign up for a plan. Most lenders run a "soft" credit check, meaning that your score should not decrease. Your payment history may or may not be reported to the credit bureaus, depending on the service used. Reading the fine print to understand how the loan may affect your credit is important. If you use a service that reports to the credit bureaus, your payments will affect your credit score.