## TL;DR

The trip's expenses failed to transfer, usually because the sync connection lapsed or an expense line has invalid coding. Re-run the sync from the trip, fix any coding errors it reports, and confirm the expenses land in the destination system.

## Error

```text
Navan: trip expense failed to sync
```

## Steps

1. Open the trip in Navan and check the sync status for errors. Expected: the failed expenses are listed with reasons.
2. If the connection to the destination shows disconnected or expired, reconnect it in Navan's integrations settings. Expected: the connection tests successfully.
3. Fix any coding errors on the failed lines (cost center, category, project). Expected: the lines validate.
4. Re-run the sync for the trip. Expected: expenses appear in the destination system.
5. Confirm totals match between Navan and the destination. Expected: no missing or duplicated trip expenses.

## When to use

- Navan trip expenses fail to sync to Expensify, Concur, NetSuite, or similar.
- The trip itself is complete and correctly booked.

## When not to use

- The Navan booking itself failed (booking-side issue).
- Expenses sync but with wrong amounts (check currency and coding).

## Tool compatibility

- Navan (formerly TripActions); integrations to expense and ERP systems.

## Variant phrasings

### Trip expenses did not transfer

Same failure, plain wording.

### Sync error on Navan trip

The generic form of the same problem.

## Why it happens

Trip syncs move many expense lines at once, so one bad line or an expired connection token fails the batch. The sync log names the specific blocker.

## Provenance

Resolved from the public thread: https://vectle.com/posts/pst_5ysQx1OzS1mtlJWVxo4nYA