Twilio Error 21408

Twilio returns error 21408 with the message "Message blocked: permissions disabled for the destination region." In most cases this is a Geo Permissions block: your account is not currently allowed to send SMS to the country the To number belongs to. But the same error code can also fire when the destination isn't supported for the channel you're sending on, or when the destination is blocked by regulation — neither of which Geo Permissions can fix.

What causes Twilio Error 21408?

Twilio's Messaging Geo Permissions gate outbound SMS by destination country so accounts don't incur unexpected charges or fraud exposure in regions they don't operate in. Error 21408 fires when:

• The destination country is disabled in your account's SMS Geo Permissions.
• Your account is new. By default a new account can only message the home country verified at signup until you enable additional destinations.
• The To number has the wrong country code. Geo Permissions are evaluated by destination country code, so a malformed or mis-prefixed number can resolve to a country you have not enabled.
• A subaccount inherits a restrictive parent setting, or the parent's permissions changed.
• Your channel doesn't support the destination. For WhatsApp and RCS, Twilio blocks certain destinations (for example, numbers starting with +98) regardless of your Geo Permissions settings — there is no toggle to enable these.

Note that some destinations are blocked by regulation and cannot be enabled via Geo Permissions at all (Twilio halted traffic to Iran, and later Syria and Cuba) — those produce related blocks you cannot toggle off.

How do I fix Twilio Error 21408?

The steps below fix the Geo Permissions case, which is the most common cause. If your destination is unsupported for the channel (WhatsApp/RCS) or blocked by regulation, there is no Console setting that will resolve it — you'll need to use a supported channel or destination instead.

1. In the Twilio Console, go to Messaging > Settings > Geo Permissions (SMS Geo Permissions).
2. Find the destination country using the filter or continent list, and check the box next to it to enable it.
3. If the country is flagged High Risk for SMS fraud, you must also tick the acknowledgement confirming you accept the added risk and financial exposure.
4. Click Save geo permissions and confirm. Changes take effect immediately, so you can retry the send right away.

A few important details:

• Only Account Owner and Account Admin users can change Geo Permissions, and there is no API to change them — it must be done in the Console.
• Subaccounts inherit the parent account's permissions by default; if you use subaccounts, verify the setting on the account actually sending the message.
• Before enabling a new country, confirm the To number's country code is correct (E.164 format). If the number is wrong, fixing the number — not the permission — is the real fix.

Reference: Twilio Error 21408.