The WhatsApp Business Platform with Twilio: Best Practices and FAQs

What are the requirements for a business to be approved for WhatsApp?
WhatsApp requires compliance with the WhatsApp Business Solution Terms, with the WhatsApp Business Messaging Policy, and with its Commerce Policy. As part of the approval process, the business and use case will be considered to make sure the usage is in line with the above guidelines.

What is the cost of the WhatsApp service?
WhatsApp service is charged per message fees. Meta also charges fees per 24 hour window for each conversation which are passed on to you by Twilio. There are two types of conversations: Business-initated conversations and user-initated conversations. Business-initiated conversations can fall into three categories, depending on the category of the template used: marketing, utility or authentication. All Meta fees vary by country, based on the end-user's country code. You can find more information about the cost of sending WhatsApp messages here.

How can I manage separate access lists to Sandbox and to the live numbers on my account?
If you have the need to segment traffic and manage separate access lists, we recommend that you split the traffic between different Twilio accounts. This will allow you to have better control over each one of these use cases and will allow you to manage separate access lists for each account.

What is the MPS (Messages Per Second) limit for outbound WhatsApp messages?

The WhatsApp Business Platform with Twilio supports a messaging throughput of 80 MPS (messages per second) by default per WhatsApp sender for outbound traffic. This throughput applies to both messages containing text-only and messages containing media files. The text-only throughput for a WhatsApp sender can be increased up to a maximum of 400 MPS by request and pending approval upon review of the business's messaging requirements. Media throughput cannot be increased further at this time.

Messages sent at rates exceeding the configured throughput for the sender will be sent to a message queue and dequeued for delivery at the throughput rate set. This message queue has a maximum limit of four hours. Messages that remain in the queue for more than four hours will fail. New messages that will cause the queue to back up beyond the four hour time limit will be rejected and fail.

• If you require sending messages at high MPS for more than a few minutes, contact our support team for guidance and best practices prior to your campaign.
• Factors that may lead to lower throughput include sending large media files, sending high volumes of unique media files to each recipient user, sending messages containing URLs to websites with long load times, receiving concurrent inbound messages on the same WhatsApp number that is sending outbound notifications, and high network latency between servers and recipient users.

If you need higher MPS beyond what we can provide you per sender, you can use Messaging Services. This allows you to distribute high message volumes across many senders within a messaging service. You may also refer to our article on Scaling WhatsApp for additional best practices.

Why am I getting a message "your number is not associated with the sandbox channel"?
Be sure you follow the instructions in the Using Phone Numbers with WhatsApp section of the Programmable Messaging API Reference and Overview carefully. You'll need to join a sandbox, as well as enable one of your Twilio numbers with WhatsApp.

Why am I getting a message "Twilio could not find a Channel with the specified From address" when trying to send a message?
There are two common reasons why you are seeing this error:

• The From address in your Programmable Messaging API request is incorrect. To send messages using WhatsApp, the From address should be whatsapp:<sandbox phone number>. This can be found on the sandbox page.
• You are trying to send a message from an account that does not have that sandbox installed. Activate the sandbox before sending a message.

I joined the Twilio sandbox for WhatsApp and got a "Twilio Sandbox. You are all set! The sandbox can send/receive messages..." reply. Can I change the message?
This reply is part of our sandbox implementation and cannot be changed. Once you get your own number, you are free to set your own message. Just keep in mind that WhatsApp requires brands to receive customer opt-in before sending messages on WhatsApp.

My outbound message from the sandbox was not delivered. Why?
There are two reasons why a message sent from the Twilio Sandbox for WhatsApp would fail to be delivered:

• You are trying to send a message to a user who has not joined your sandbox. See our instructions for getting started with the sandbox, including how users can join your sandbox.
• You are sending a free-form message outside the WhatsApp session to the user. A WhatsApp session lasts for 24 hours after the last inbound message you receive from a user. Outside a WhatsApp session, you may only send a pre-approved template message to the user (for more details read up on template messages); any message that doesn't match a pre-approved template will be sent by Twilio as a free-form message. You can find a list of templates pre-approved for the sandbox in the templates pre-registered for the Sandbox docs.