42min

    Help Integrations

    Twilio (SMS)

    Connect your organization's Twilio account and 42min sends your workflow SMS from your Twilio phone number or Messaging Service. Twilio bills the texts to your Twilio account; 42min adds no charge. You set it up on the Integrations page, under Messaging.

    What it does

    • Connect with your Twilio Account SID and Auth Token. 42min checks them with Twilio before saving (a suspended or closed Twilio account is refused) and stores them encrypted.
    • Pick the sender: one of your SMS-capable phone numbers, or a Messaging Service whose sender pool can send SMS.
    • Send SMS steps from your workflows: SMS to invitee and SMS to host.
    • Send a test SMS to check everything works.
    • Track delivery: 42min checks each text's status with Twilio, and shows it in Sent messages.
    • Honor STOP replies: when an invitee replies STOP to your number, 42min stops texting them about that booking.

    Before you start

    • You need a sender in Twilio: a phone number with SMS capability, or a Messaging Service that has one (or a short code or alphanumeric sender) in its pool. See Twilio's guide on getting a phone number.
    • Texting US numbers needs registration. US carriers accept texts only from an A2P 10DLC registered number or Messaging Service, or a verified toll-free number.
    • Trial accounts are limited. A Twilio trial account texts only numbers verified in that account, and Twilio adds a trial notice to each text.

    How to connect

    Connecting is admin-only.

    Integrations → Messaging: Twilio is the middle tile; click its Connect button to start.
    1. Open the Twilio Console and copy the Account SID and Auth Token from its home page.
    2. In 42min, open Integrations, find Twilio under Messaging, and click Connect.
    3. Paste the Account SID and Auth Token and confirm. If Twilio rejects them, check you copied both values in full (the Account SID starts with AC).
    4. Choose the Sender. The list has two groups, Phone numbers and Messaging Services. If both are empty, your account has nothing that can send SMS yet.
    5. Leave Use Twilio to send SMS ticked (it's ticked for you when no other provider sends your SMS) and save.
    The Connect Twilio window: paste the Account SID and Auth Token from your Twilio Console home page.
    After Connect: pick the Sender (the dropdown groups Phone numbers and Messaging Services), keep Use Twilio to send SMS ticked, and Save.

    The Twilio tile then shows Connected, the sender, a Use to send SMS checkbox, and a link to Settings.

    Settings

    The Twilio settings page has three parts:

    The Twilio settings page: Connection (with your balance, Update keys and Disconnect), SMS sending, and Send a test SMS.
    • Connection: who connected it, the last four characters of the Account SID, the status, the last error (if any), and your live Twilio balance. Update keys swaps in a new Auth Token or account (checked before the old keys are replaced), and Disconnect removes the connection.
    • SMS sending: the Sender and Use to send SMS.
    • Send a test SMS: enter a mobile number (prefilled with yours from your profile) and send. Twilio charges it like any other SMS. You can send 5 test SMS every 10 minutes.

    One provider at a time

    Your organization sends all its SMS through one provider. If you also connect SendPulse, ticking Use to send SMS on one tile unticks it on the other. Both connections stay saved, so you can switch back at any time.

    STOP replies

    Twilio blocks texts to anyone who has replied STOP to your sender. When that happens, 42min turns off SMS for that invitee's booking (and the later meetings of a recurring series), the same as if they had clicked Stop texts on their cancel or reschedule page. Their remaining SMS steps for that booking are skipped with no SMS consent.

    Common pitfalls

    • A Messaging Service is missing from the list. Only services whose sender pool can send SMS are offered. Add an SMS-capable number to the service in Twilio.
    • Texts to US numbers fail. The number or Messaging Service isn't registered for A2P 10DLC (or the toll-free number isn't verified). The Twilio error shows on the Failed status in Sent messages.
    • Texts fail with Twilio error 21610. The recipient replied STOP to your sender. 42min stops texting them about that booking. Nothing needs fixing on your side.
    • Connection broken. Twilio stopped accepting the saved keys (for example, the Auth Token was rotated). Open Settings and Update keys. SMS steps are skipped until then.
    • Disconnecting. 42min deletes the saved keys; nothing changes in your Twilio account. If Twilio was sending your SMS, workflow SMS steps are skipped until you connect a provider again.

    Last updated September 18, 2026.

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