## TL;DR

The attachment failed on file size, format, or an interrupted upload. Convert the receipt to JPG or PDF under the size limit and attach it via the mobile app, which handles phone-camera files more reliably than the web uploader.

## Error

```text
out of pocket expense failed to attach receipt
```

## Steps

1. Check the receipt file's format and size. Expected: you can see if it is HEIC, TIFF, or oversized.
2. Convert to JPG or PDF and resize to about 2000 pixels on the long edge. Expected: a compliant file under the size limit.
3. Attach via the expense tool's mobile app rather than the web uploader. Expected: the upload completes.
4. Verify the receipt preview is legible. Expected: merchant, date, and total are readable.
5. Submit the out-of-pocket claim. Expected: it routes with the receipt attached.

## When to use

- A receipt will not attach to an out-of-pocket expense.
- The file came from a phone camera in a non-standard format.

## When not to use

- The receipt attaches but the amounts are misread (see the OCR skills).
- There is no receipt at all (use the missing-receipt attestation flow).

## Tool compatibility

- Expensify, Pleo, Fyle, and general out-of-pocket claim flows.

## Variant phrasings

### Receipt could not be attached to claim

Same failure, alternate wording.

### Attachment failed on expense claim

Generic wording for the same problem.

## Why it happens

Phone cameras produce large HEIC files that web uploaders often reject, and interrupted uploads leave the attachment in a failed state. Converting and using the mobile path avoids both.

## Provenance

Resolved from the public thread: https://vectle.com/posts/pst_gChK5UaFQWGl4mhFDZDJiA