Twilio limits US message throughput from 19 November 2026 to 4 January 2027: plan peak-season SMS now

Twilio limits US message throughput from 19 November 2026 to 4 January 2027: plan peak-season SMS now

1 October 2026 — Twilio, the communications API used by many businesses to send text messages, has announced its 2026 Heightened Awareness Period (HAP): from Thursday 19 November 2026 to Monday 4 January 2027. During that time, Twilio says, "message sending rates to U.S. destinations will be monitored and may be limited at the account level for toll-free, short code, and 10DLC numbers". The period covers Black Friday, Cyber Monday and the holiday season, when message traffic peaks.

Not yet independently verified. This rests on Twilio’s own changelog entry of 17 September 2026; no independent report was found. Twilio publishes no per-account limits, and says affected customers will be told by email. We will update this when it can be confirmed, and remove this note.

What changes

• Sending rates to US numbers are monitored and may be capped per account, for toll-free numbers, short codes and 10DLC (local long codes registered for business messaging).
• High-volume short code and toll-free senders "may be temporarily migrated to Market Throughput" during the period. Twilio says customers will be notified by email if their account is affected.
• 10DLC numbers are not moved: they "will continue to live on Account Based Throughput".
• Twilio asks customers to contact their account team about how throughput limits may affect them and what to do.

Who is affected

Retailers and marketplaces planning holiday campaigns, delivery and logistics firms sending notifications, banks and fintechs sending one-time passcodes, and the software platforms that send SMS for their own customers through Twilio. A promotional blast that ran in minutes last month may take much longer during the period, and in the worst case time-sensitive messages queue behind it.

What to do

• Talk to your Twilio account team now about expected volumes on each sender type, before the period starts.
• Separate critical traffic, such as passcodes, delivery alerts and fraud warnings, from marketing on different senders, so that a campaign cannot slow them down.
• Spread big campaigns across the day and over several days around Black Friday instead of one send.
• Watch for Twilio's email saying your account has moved to Market Throughput, and check your queueing and retry logic handles slower sending.
• If you resell SMS through Twilio, tell your own customers about the period and any limits you will apply.

Sources

• Twilio Changelog: Twilio Heightened Awareness Period (HAP) – November 19, 2026 - January 4, 2027 — 17 September 2026