xms_tcdt — Tenant Creation Time

Location: payload · Format: timestamp · Vendor: Microsoft Entra

Unix epoch seconds when the token's tenant was created. Occasionally used as a coarse signal to distinguish long-established organizations from newly-created (and potentially throwaway/attacker-created) tenants.

Defined in Microsoft identity platform token reference.

Decode a JWT and inspect its xms_tcdt claim in the TokenPrism debugger — free, entirely in your browser.