A successful response confirms that Insider One received the request. These APIs change who you can contact, so verify every change in the InOne panel before you run them in production.
Use a test address you own. With email as the identifier, unsubscribing an address that has no profile creates one. If the email-based subscription flow is enabled on your account, the address is suppressed without a profile being created, so create the test user first if you want to see it in User Profiles. Without PII access, the addresses on the suppression lists are masked, so you cannot confirm your test user. Ask an Administrator for PII access or have them check for you.
Check the result in the InOne panel
For unsubscribe and resubscribe calls, go to Audience > Suppression > Global Unsubscribe or Unsubscribe Groups.
On Global Unsubscribe, switch between the Email, SMS, and WhatsApp tabs, depending on the products enabled on your account. Search for the test user. The user appears on the list after an unsubscribe and no longer appears after a resubscribe.
A 200 response means the request was queued, not applied. Changes usually show within a few minutes. Large batches and group operations take longer.
Go to Audience > User Profiles and open the profile. A global unsubscribe sets email_optin to false and global_unsubscribe to true on the Overview tab. A resubscribe reverses both. A group unsubscribe does not change email_optin.
For deletion calls, search for the user in User Profiles. A deleted profile no longer appears.
Removing a contact from Global Unsubscribe resubscribes them: the user becomes reachable for email again. Only do this for users who have opted back in.
Read the response
The response contains only statusMessage. A 200 means the whole request was accepted for processing. It does not confirm each identifier. Invalid identifiers inside an accepted batch are skipped without an error, so verify in the panel.
A request accepts up to 500 identifiers. An unsubscribe with a group name that does not exist creates a new group, so a typo creates a group. To remove a user from a group, resubscribe with the group_id: a plain resubscribe does not remove group membership. If the email product is not enabled on your account, the API returns 200 with a message that the product is not activated, and it does nothing.
Reproduce a failure in Postman
Open the endpoint page and select Run in Postman. The Insider One Postman documentation opens at that endpoint.
In the top right corner of the Postman documentation, select Run in Postman.
In the Fork collection into your workspace window, select Fork Collection. Postman opens the collection in the Postman app or in your browser.
Select the environment that holds your tokens. The unsubscribe and resubscribe endpoints need both the X-REQUEST-TOKEN and the X-PARTNER-NAME headers. A single API key returns 401 on one of them.
In the Body tab, select raw and paste the payload from your integration.
Select Send and compare the response with your integration log.
Reduce the payload to one identifier, then add identifiers back until the error returns.
Remove the API key and personal data before you share the request or response.
To trigger a known error on V2, send an empty emails array or more than 500 identifiers. Both return 400. A malformed address inside a valid batch does not return an error. On V1, an invalid identifier returns 400.
For more information, see Insider One APIs in Postman and API Status and Error Codes.