---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/80406#article
headline: "80406: Phone Number Did Invalid"
url: https://www.twilio.com/docs/api/errors/80406
inLanguage: en
dateModified: 2026-06-08T12:04:59.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 80406: Phone Number Did Invalid

Log Level: WARNING

## Description

This warning occurs when your Proxy request includes an invalid phone number value for a Proxy phone number. When you add a phone number to a Proxy Service, send either `PhoneNumber` in `E.164` format or `Sid` for the Twilio IncomingPhoneNumber resource on your account.

### Possible causes

* The `PhoneNumber` value is not formatted in `E.164`, which requires a leading `+`, country code, and subscriber number.
* The phone number contains invalid characters or is incomplete.
* The request uses a phone number value that does not match the Twilio number you intended to add to the Proxy Service. Proxy phone number pools use Twilio phone numbers associated with the service.

### Possible solutions

* Update the `PhoneNumber` value to valid `E.164` format, for example `+14155551234`.
* If you already know the Twilio number resource SID, use `Sid` instead of `PhoneNumber` when you add the number to the Proxy Service.
* Confirm that the number you are adding is a Twilio phone number on your account and that you are adding it to the correct Proxy Service.

#### Additional resources

* [Proxy PhoneNumber resource](/docs/proxy/api/phone-number)
* [Proxy Quickstart](/docs/proxy/quickstart)
* [What is E.164?](/docs/glossary/what-e164)