Phone Number Formatting

Last updated: April 12, 2026

Last Updated: April 12, 2026

Customer-Facing Guide

Overview

A large percentage of send failures come from bad phone formatting. Before troubleshooting anything deeper, make sure the recipient number is complete and formatted in a way Sendblue can use reliably.

Safe default format

Use full E.164 formatting whenever possible, for example +14155559988.

Common bad examples

  • 5551234 — missing area code

  • (415) 555-9988 ext 2 — extra text / extension in the field

  • 415.555.9988? — stray characters

Common good examples

  • +14155559988

  • +12135551234

If you are using Zapier or another automation tool

  • Normalize the phone number before sending it to Sendblue.

  • Make sure the field includes the area code.

  • Avoid sending extension text or descriptive text in the same field.

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