Errors
account_changed
HTTP status: 409
What happened
The user ID in Sendtier-Expected-User differs from the account authenticated by your dashboard
session cookie. Another tab may have signed in to a different account. The request made no changes;
a rejected sign-out also preserves your cookies.
How to fix
Refresh your account details and review which account is signed in before repeating the action.
Send that account's usr_... ID in Sendtier-Expected-User. The optional header only checks the
expected account; it never authenticates a request or overrides the session cookie.
Source: docs/errors/account_changed.md. All error codes