---
title: 1002: Phone number must be in E.164 format | API Docs
description: Phone numbers must conform to E.164 format (e.g., +14155551234).
---

Phone numbers must conform to E.164 format (e.g., `+14155551234`). This is an HTTP 400 error indicating the phone number in your request is not properly formatted.

## Troubleshooting

- Include the country code with a `+` prefix (e.g., `+14155551234` for a US number)
- Remove any spaces, dashes, or parentheses from the phone number

## Related

- [Sending messages](/guides/messaging/sending-messages/index.md)
- [API reference: Chats](/api/resources/chats/index.md)