---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/21263#article
headline: "21263: Invalid Answering Machine Detection Parameters"
url: https://www.twilio.com/docs/api/errors/21263
inLanguage: en
dateModified: 2026-03-11T18:38:39.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 21263: Invalid Answering Machine Detection Parameters

Log Type: APPLICATION

Log Level: WARNING

## Description

Invalid Answering Machine Detection Parameters

### Possible causes

AsyncAmd, AsyncAmdStatusCallback, and/or AsyncAmdStatusCallbackMethod parameters from `POST` to /Calls API have been passed in a `POST` to /Participants API, or added to `<Dial><Number>` or `<Dial><Sip>` TwiML.

### Possible solutions

Do not include AsyncAmd, AsyncAmdStatusCallback, or AsyncAmdStatusCallbackMethod parameters in `POST` requests made to /Participants API and in TwiML responses that include `<Dial><Number>` or `<Dial><Sip>` with Answering Machine Detection enabled.