Align your API integrations with good security practices by rotating your client secrets regularly.
Where: These changes apply to Marketing Cloud Engagement Pro, Corporate, and Enterprise editions.
Updated Expiration Policy for Client Secrets for API Integrations
Beginning March 23, 2026, all client secrets for API integrations have a 180-day expiration
period, which begins when you generate the secret. Client secrets generated before this date
expire on September 30, 2026. Newly generated client secrets contain 64 characters and begin
with SFMC_. To view expiration dates for your client secrets, see the
summary table on the Installed Packages page in Setup.
SEE ALSO | Marketing Cloud Engagement APIs and Programmatic Languages: Rotate an OAuth 2.0 Secret