PayPal IPN Service Errors from November 12–18, 2025: Here’s What Happened

If your site relies on PayPal for recurring subscriptions, you may have noticed something strange between November 12–18, 2025: recurring transactions were processed by PayPal, but your site never received them.

This was not a bug in your site, Paid Memberships Pro, or your server. This was an issue on PayPal’s end, with their IPN verification endpoint, the one used to confirm incoming recurring payment notifications. During this time frame, PayPal incorrectly returned HTML error pages instead of the expected VERIFIED or INVALID responses.

Keep reading to understand what went wrong and how to get order data back in sync by resending IPN history to your membership site.

What Went Wrong During the November 2025 PayPal IPN Verification Failures

For sites that use PayPal IPN (Instant Payment Notification), every incoming message is sent back to PayPal’s endpoint (https://www.paypal.com/cgi-bin/webscr?cmd=_notify-validate) for validation.

This is an important step to confirm that the IPN message coming into your site is a legit message related to your site and PayPal account.

1. For several days, if the IPN included both business and amount parameters, PayPal responded with the HTML of an error page instead of the proper validation response.
2. That meant your site would mark the IPN as INVALID and skip processing it.
3. Your membership site wouldn’t create an order, even though PayPal successfully charged the customer.

We confirmed this was a PayPal-side issue and even reproduced it by hitting the validation URL manually in a browser.

PayPal fixed their validation response on November 18th, 2025 in the early morning hours.

From that point forward, the validation endpoint is back to working as expected. You should no longer be seeing new missing orders for PayPal recurring payments.

What You Should Do Now

You should resend any PayPal IPNs that your site may have skipped during this time.

Focus especially on recurring payments made between November 12–18, 2025 that are not represented in your site under the Memberships > Orders list.

Paid Memberships Pro is smart about processing IPN data. For example, if you resend IPN for an order that was already created, your membership site will not create a duplicate.

What You Can Do If This Happens Again

If this happens in the future, and you do not have confidence that PayPal will resolve their IPN validation system quickly, there is a way to validate IPN locally.

To unblock site renewals while PayPal was broken, you can deploy a temporary fallback validation rule to accept IPNs as valid based on controlled, custom logic. This is a workaround, not a general solution, and it’s not something we recommend unless you know exactly what you’re doing.

Blindly accepting all IPNs as valid is dangerous and opens the door to fraudulent transactions.

If you’re a developer you can build your own local fallback for future incidents. To do this, create a custom validator using the pmpro_ipn_validate filter. But you should only use this in extreme edge cases, with logic specifically tailored to your site’s expected payment patterns.

Here are two examples of checks developers could use inside a pmpro_ipn_validate override to make it less dangerous than blindly returning true.

Always use multiple checks together. One check alone is not safe.

• Check the known business email. The PayPal IPN will include an attribute business. Compare this value to your PayPal business account’s email address. This is one way to confirm that your account actually sent the IPN.
• Check the payment amount. Subscription sites know what various payment amounts they’re expecting. Check the amount attribute of the IPN response. It should match some value in an array of common payment amounts based on your membership site pricing.

You can find the full list of potential IPN attributes to check in the IPN History section of your PayPal account. View a recent IPN event to see what other attributes you can use to build a secure, redundant local validator.

Have questions about this issue? Reach out to our support team anytime.