## TL;DR

Meals and entertainment expenses require an attendee list for audit, and the expense was submitted without one. Add every attendee (name and company), save, and resubmit; the validation passes once the list is present.

## Error

```text
expense failed: attendee list required
```

## Steps

1. Open the flagged meals or entertainment expense. Expected: the attendee field is empty.
2. List all attendees: names and their companies, including yourself. Expected: a complete list.
3. Enter the attendees in the expense's attendee field. Expected: the field shows every attendee.
4. Check the business purpose is also filled in, since the two often go together. Expected: both fields complete.
5. Resubmit. Expected: the attendee validation passes.

## When to use

- An expense fails validation requiring an attendee list.
- The expense is meals, entertainment, or client hospitality.

## When not to use

- Only a business purpose is missing (see the business-purpose skill).
- The attendee list exists but the approver questions it (clarify in comments).

## Tool compatibility

- SAP Concur, Expensify, and policy-audited expense tools.

## Variant phrasings

### Attendees required for this expense

Same requirement, shorter wording.

### Please list all attendees

The inline prompt form of the same validation.

## Why it happens

Tax and policy rules require knowing who benefited from meals and entertainment. The attendee list is the audit evidence, so validation blocks the expense until it is provided.

## Provenance

Resolved from the public thread: https://vectle.com/posts/pst_fiewqOYnr-W_dEjRoaLFIQ