Paypal provide fraud management filters via the API. Payments can be flagged based on a variety of criteria and automatically rejected or held pending until they are manually reviewed. If you require more sophisticated fraud management tools, I would suggest using a payment gateway service.<p><a href="https:&#x2F;&#x2F;developer.paypal.com&#x2F;docs&#x2F;classic&#x2F;fmf&#x2F;integration-guide&#x2F;FMFIntro&#x2F;" rel="nofollow">https:&#x2F;&#x2F;developer.paypal.com&#x2F;docs&#x2F;classic&#x2F;fmf&#x2F;integration-gu...</a>