## TL;DR

Twilio 20404 means the message SID does not exist (or belongs to a different account): check the SID and the account it is fetched with.

## Error

```text
Twilio error 20404: The requested resource was not found
```

## Steps

1. Verify the message SID is complete and correct Expected: no truncation or typo.
2. Fetch it with the same account that sent it Expected: account matches.
3. Check whether the message was deleted Expected: you know if it is gone for good.
4. Fix the SID source if automation mangles it Expected: future fetches work.

## When to use

- Twilio 20404 on message fetch
- The SID is wrong or cross-account

## When not to use

- The message exists (then check the account)
- Recently sent (then allow for propagation delay)

## Tool compatibility

- Twilio message SIDs
- SMS integrations

## Variant phrasings

### twilio 20404

The message was not found. Check the SID and the account.

### requested resource not found twilio

Same: wrong SID, wrong account, or deleted message.

## Why it happens

SIDs get truncated in logs and UIs, and subaccounts split resources. Agents fetch with whatever account is configured.

## Edge cases

- Message resources are immutable; a 20404 never becomes a 200 later
- Store the full SID at send time

## Provenance

Resolved from the public thread: https://vectle.com/posts/pst_n78JVIgnJzEdSs6M2wi-hw