👇 Tap me
▶ Hear PJ — 20 sec
The code sends fine but arrives 30–90 seconds late — sometimes never. Users give up before it arrives. In 2026 this is almost always queue congestion, carrier routing lag, or the wrong channel for the number type.
Standard A2P long codes process 1 message per second. During peak hours or burst verification events (new user signups, login spikes), messages queue at Twilio. Users who trigger verification during a queue backup see 30–120 second delays. Use a toll-free number or short code for time-sensitive verification flows.
SMS doesn't travel a direct path — carriers route through intermediaries that vary by time of day and load. Some carrier-to-carrier routes have 30–60 second latency built in. Twilio's Verify product tries to optimize this, but the underlying carrier route is not guaranteed to be the fastest one.
For international numbers, SMS can be significantly slower than WhatsApp or voice OTP. Twilio Verify supports fallback channels — if SMS hasn't been received within N seconds, automatically retry via voice call. Configure this in your Verify service settings.
Twilio Verify can be configured with channel fallback: SMS → voice. If you're only using SMS and it's slow for a subset of users, those users may be on carriers with slow SMS routing. Enable voice fallback with a 20–30 second timeout to dramatically improve success rate.
If your backend makes a Twilio API call on a slow server or during cold start (serverless function), the API call itself adds latency before Twilio even sends the message. Log the time between user action and Twilio API call to isolate whether the delay is on your side or Twilio's.
Real operator. No ticket queue. San Diego-based. Most issues resolved in one thread.
Related problems in this cluster: