---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/13248#article
headline: "13248: Dial: Invalid callerID, too long"
url: https://www.twilio.com/docs/api/errors/13248
inLanguage: en
dateModified: 2026-06-08T11:29:20.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 13248: Dial: Invalid callerID, too long

Log Level: WARNING

## Description

Twilio raises this warning when the `callerId` attribute on `<Dial>` contains more characters than the caller ID value Twilio accepts for the destination you are dialing. Use a valid phone number for `<Number>`, a valid client identifier for `<Client>`, or an allowed caller ID string for `<Sip>`. For SIP dialing, `callerId` can contain alphanumeric characters and the optional characters `+`, `-`, `_`, and `.`, with no whitespace.

### Possible causes

* You set `callerId` to a phone number that exceeds the maximum length for E.164 numbers. E.164 numbers can contain up to 15 digits.
* You are dialing a `<Client>` and the client identifier used as `callerId` is longer than 256 characters.
* The `callerId` value does not match the type of destination you are dialing. `<Dial>` expects a phone number for `<Number>`, a client identifier for `<Client>`, or an allowed SIP caller ID string for `<Sip>`. Using a longer display string or other nonstandard value can trigger this warning.

### Possible solutions

* If you are dialing a phone number with `<Number>`, set `callerId` to a valid E.164 phone number and keep it within 15 digits. Use only a Twilio number on your account, the inbound `To` or `From` number when allowed, or a phone number you verified with Twilio.
* If you are dialing a `<Client>`, shorten the client identifier to 256 characters or fewer. Remove spaces, control characters, delimiters, and unwise characters. If you use a mobile Voice SDK identity, use only alphanumeric characters and underscore.
* If you are dialing a `<Sip>` endpoint, replace the `callerId` value with a simple caller ID string that contains only alphanumeric characters and the optional characters `+`, `-`, `_`, and `.`, with no whitespace.
* Validate and trim the `callerId` value before you return TwiML or create the call. This helps prevent extra characters from being passed into `<Dial>`.

#### Additional resources

* [TwiML Voice: `<Dial>`](/docs/voice/twiml/dial)
* [TwiML Voice: `<Client>`](/docs/voice/twiml/client)
* [OutgoingCallerIds resource](/docs/voice/api/outgoing-caller-ids)