## Important Notice for sites running on WordPress
CiviCRM 5.26 and later changes how front-end CiviCRM URLs are formed in WordPress.
Please [read this blog post before upgrading](https://civicrm.org/blog/kcristiano/civicrm-526-and-wordpress-important-notice).
You may need to update settings at your payment Processor for recurring payments.
If you have an external service that sends callback messages to CiviCRM, you may need to update the settings at the external service to use the new URL format.
## NOTICE: WordPress Service URLs
The upcoming release of WordPress 5.5 (ETA July 2016) requires changes to several CiviCRM URLs. CiviCRM 5.26+ adopts a new URL convention. For old URLs, there is transitional support that will work for most web-based visitors. However, this may not be sufficient for *external service integrations* (e.g. certain payment processors or email relays which send notifications to CiviCRM). Administrators should promptly assess and update any external services which submit notifications to their CiviCRM-WordPress sites.
For more information, see the blog post [CiviCRM 5.26 and WordPress: Important notice](https://civicrm.org/blog/kcristiano/civicrm-526-and-wordpress-important-notice).
