Verification code fallback solution
This feature improves the delivery rate of verification code messages by providing a fallback solution. If a message fails to send, for example, due to a pending carrier review, the system automatically switches to a fallback signature and template.
The verification code fallback solution is currently in an invitation-only phase and is available only to customers who work directly with Alibaba Cloud.
Enable the fallback solution
This optional service acts as a backup, helping you send verification codes securely while waiting for final carrier approval. Once your custom signature and template are approved by the carrier, the system automatically uses them.
Log in to the General Settings - Domestic Message Settings page in the Short Message Service console, and click the Verification Code Failover Configuration tab.
Click the switch to the right of Verification Code Failover Solution and confirm in the pop-up window to enable the solution. Before you enable the solution, you must read the information about Limitations and Potential Impacts and Compliance Requirements on the page and agree to enable it.
If you do not apply for and use a signature as required by the carrier, or if your SMS message contains illegal or non-compliant content, the carrier will block it, causing a delivery failure. You are solely responsible for the content of your messages and any consequences. If your illegal or non-compliant message content causes losses to Alibaba Cloud or the carrier (such as SMS port suspension, regulatory notices, interviews, fines, or administrative penalties), you are liable for compensation. Alibaba Cloud reserves the right to suspend or terminate your Short Message Service.
How the fallback solution works
Ensure that you have approved SMS qualifications, a custom signature, and a verification code template.
When sending an SMS message, select your custom signature and verification code template. The template must contain the verification code parameter named
${code}.Example: [Your custom signature] You are registering a new account. Your verification code is: ${code}. Do not share it with others.
When you call an API such as the SendSms API, continue to pass your custom signature in the
SignNameparameter. You do not need to change your API calls. The system automatically switches to the fallback signature for redelivery if the original attempt fails.By default, messages are sent using your custom signature and template. If a delivery fails, the system switches to the fallback signature and template and extracts the value passed to the
${code}parameter. The final message combines the fallback signature, your custom signature, and the${code}value.Example: [Fallback signature] Dear user, your "custom signature" verification code is: ${code}. Do not share it with others.
View fallback signature data
After enabling the fallback solution, the system provides a fallback signature. To distinguish it from your own signatures, this signature is marked with the Failover Signature label.
For verification code messages sent using the fallback signature, all related data, such as delivery records, delivery statistics, and bills, are associated with the fallback signature. You cannot query this data using your original signature. On relevant statistics pages, any fallback signature with delivery records automatically appears in the signature selection box, allowing you to filter and view its data.
View delivery records
Log on to the Short Message Service console and go to the Business Statistics > Delivery Records page.
On the Query Messaging Records and Failure Cause Analysis tabs, select the fallback signature to view its related delivery data.
If you query delivery records by phone number, the Signature column shows the fallback signature, and the Message Content column shows the full content, which combines the fallback signature, your custom signature, and the verification code.
View delivery statistics
Log on to the Short Message Service console and go to the Business Statistics > Delivery Statistics page.
You can view delivery data for signatures that have the Fallback signature label.
View costs
Log on to the Short Message Service console and go to the Cost > Custom Bills page.
Set up your custom bill and select Signature as the bill split item.
You can then view the detailed costs generated by the fallback signature.
FAQ
Configure fallback for each signature?
No. After enabling the fallback solution, the system automatically uses it when a message sent with any of your eligible custom signatures and templates fails. This feature only applies to verification code templates that use ${code} as the parameter name for the verification code.
Does fallback affect expiration time?
No, the validity period of the verification code is not affected. The message sent using the fallback signature and template does not display an expiration time, but the actual validity period still depends on your application's backend settings.
How long to take effect?
After you enable the solution, it typically takes effect within 10 minutes.
Is there a fee?
The verification code fallback solution is currently in a free trial period. We will notify you and post an announcement if there are any changes.
Billing for fallback messages?
During the free trial period, messages sent using this feature are billed the same as regular messages. Both pay-as-you-go and resource plan billing methods are supported.
Will signatures alternate?
Yes. If a message sent with your custom signature fails, the system automatically switches to the fallback signature. This can result in messages being sent alternately with both your custom signature and the fallback signature.
Can I choose a fallback signature?
No. The system selects a fallback signature based on internal policies. You cannot customize this selection.
What if the parameter is not ${code}?
Currently, the fallback solution only works with standard verification code templates where the parameter is named ${code}. If your template uses a different parameter name, you cannot use this feature.
Manual disabling required?
Yes, you must disable it manually, as the fallback solution does not deactivate automatically. To disable it, log on to the Short Message Service console, go to the **General Settings** > **Domestic Messages Settings** page, click the Verification Code Failover Configuration tab, and then turn off the switch next to Verification Code Failover Solution. After you disable it, the system will no longer switch to the fallback signature. If a message sent with your custom signature fails, the delivery will not be retried, and your verification code delivery rate may decrease.
Still need the fallback solution after signature registration?
Check the carrier registration result on the Signatures page in the Short Message Service console. For each signature, the page shows the registration result separately for China Mobile, China Unicom, and China Telecom, for example, Registered, pending verification or Registration failed.
Registered, pending verification means that at least one carrier sub-channel has returned a registration result, but actual delivery is not confirmed yet. You can use the one-click test on this page to verify actual delivery with the registered signature.
If you send a high volume of messages and currently rely heavily on the fallback solution, we recommend that you keep it enabled until registration is confirmed with all carriers, to avoid fluctuations in the delivery rate. If your message volume is low, you can disable the fallback solution manually after the registration result is confirmed.
After your custom signature and template are approved by the carrier, the system automatically switches back to your custom signature and template. You do not need to switch back manually. If you still want to disable the fallback solution, go to the General Settings > Domestic Messages Settings page, click the Verification Code Failover Configuration tab, and then turn off the switch next to Verification Code Failover Solution.
Does the fallback solution still work if all my signatures fail registration?
Yes. The verification code fallback solution uses a general fallback signature provided by Alibaba Cloud and does not depend on the registration status of the signatures in your account. Even if all of your own signatures fail registration, as long as the verification code fallback solution is enabled, the system still switches to the fallback signature when a verification code message fails to send. The fallback solution covers only verification code messages. For notification messages, you must enable the notification fallback solution.