Overview

If you send text messages to UK mobile numbers through Enrollio, your message deliverability and compliance are at risk unless you update your sender types.

Starting June 1, 2023, UK carriers began blocking international long codes for Application-to-Person (A2P) traffic. In 2024, stricter regulatory requirements were introduced for UK long codes themselves.

What Changed in 2023

Carrier Blocking of International Long Codes

From June 1, 2023, UK network operators started blocking text messages from non-UK long codes. These numbers were originally designed for Person-to-Person (P2P) use, but many businesses were using them for A2P traffic, which carriers now classify as abuse of P2P routes.

Impact: Any text message sent to UK parents or families from an international long code is likely to fail.

What Changed in 2024

Twilio and UK regulators have layered on stricter compliance requirements:

Regulatory Compliance Bundles (RC bundles)

  • From May 27, 2024, all new UK long codes require an approved RC bundle before they can send text messages or make calls
  • From September 30, 2024, all UK long codes (new or old) must have an approved RC bundle

Know Your Customer (KYC)

Businesses must provide documentation to verify their identity and intended use case before using UK long codes. This includes your childcare center's business name, address, and messaging use case.

Full Enforcement of Blocking

By mid-2024, all UK carriers had aligned to enforce these rules. Traffic from international long codes is universally blocked, and unregistered UK long codes will also fail.

What You Need to Do

Step 1: Stop Using International Long Codes

If you're still sending text messages from non-UK numbers to UK parents, switch immediately to avoid message failures.

Step 2: Use Approved Sender Types

Choose one of these compliant options:

  • UK Long Code (Local Number) — Requires KYC and regulatory approval
  • Alphanumeric Sender ID — For one-way traffic, brand your sender name (e.g., "YourCenter")
  • Short Code — For higher-volume or two-way messaging, apply for a UK short code (12–16 weeks provisioning time)

Step 3: Register Your Numbers

  1. Submit your Regulatory Compliance (RC) bundle in the Twilio Console
  2. Provide the necessary KYC documents (business name, address, use case, etc.)
  3. Wait for approval before sending messages

Step 4: Monitor Message Logs

In the Twilio Console, use Messaging Insights to filter:

  • "From Country ≠ UK" and "To Country = UK" → find non-compliant traffic
  • Look for blocked or undelivered messages and update routing

How to Buy a UK Number in Twilio

  1. Go to: Console → Develop → Phone Numbers → Buy a number
  2. Set Country = UK
  3. Uncheck Voice (if you want SMS-only)
  4. Select an SMS-capable number
  5. Complete RC bundle submission
[SCREENSHOT: Twilio Console phone number purchase screen showing UK country selection and SMS capability options]

Timeline Recap

  • June 1, 2023 → UK carriers begin blocking international long codes
  • May 27, 2024 → New UK long codes require RC approval
  • July 30, 2024 → Full carrier enforcement across all networks
  • September 30, 2024 → All UK long codes (new + existing) must have RC approval

Key Takeaways

  • International long codes cannot be used for UK text messages
  • All UK long codes now require KYC and regulatory compliance
  • Alphanumeric Sender IDs and short codes remain valid alternatives
  • Act now to avoid message failures when communicating with UK-based families
Pro Tip: If your childcare center primarily sends one-way messages (like enrollment reminders, tour confirmations, or payment notifications), an Alphanumeric Sender ID is often the quickest and most cost-effective solution for UK messaging.