Sinch Engage to Reject HTTP API Calls Oct. 31; CRM Texting Teams Should Check Connections

Sinch Engage says it will reject API requests made over HTTP beginning October 31, 2026. Sales operations teams using a custom or third-party connection to send CRM-linked texts should check the request URL: the September 30 notice says messages submitted through rejected calls will not be sent.

Existing HTTPS requests are unaffected. The cutoff depends on how a connection reaches the Sinch Engage API, rather than which CRM is on the other end. Sinch documents Salesforce messaging through its Engage API, but that does not establish whether the native integration uses HTTP. The cutoff notice names no subscription-plan exception.

Check the URL and test a message

For any integration the team manages, check whether its API request URL starts with http://. Sinch says an affected connection can be switched to https:// without changing existing credentials or integration logic, then verified with a test message. Its API reference lists HTTPS base URLs for EU, APAC and US instances; use the appropriate endpoint for the account.

For a vendor-managed connector, ask its provider which protocol the connection uses. Sinch identifies third-party apps and plugins as possible HTTP callers, rather than confirming that a particular CRM app is affected. It says account numbers and pricing are unchanged and offers no extension beyond October 31. Teams already using HTTPS, or only the Sinch Engage web application, have no HTTP API request to update under this notice.

Which published deadline applies?

An older Sinch security article, updated August 21, still lists September 30 as the date HTTP endpoints would be disabled. The newer September 30 announcement gives October 31 instead. That newer notice supplies the stated cutoff for checking affected URLs and testing message delivery.