## TL;DR
The cash that moved is defined by the bank's rate, 1.0841, so the ERP's 1.0843 booking created a paper difference that leaves the payment partly unapplied. Recompute the receipt or payment at the bank rate, adjust the entry by the penny difference to the FX account, and apply the payment in full. Then find why the rates diverged: the ERP likely used a daily table rate while the bank used its wire execution rate, which will recur on every wire until the booking process uses the execution rate.

```text
bank converted the USD wire at 1.0841 but the ERP booked 1.0843: "penny difference" error unapplied
```

## Use this when
- A wire payment or receipt is unapplied by a small amount tied to a rate difference of 1.0841 versus 1.0843.
- The bank conversion confirmation shows a different rate from the ERP entry.
- The underlying invoice or obligation is otherwise fully settled by the wire.

## Not for this skill when
- The rate difference is large or the currency amount differs too. That is a wrong-amount wire, not a penny difference.
- The contract fixes a rate different from the bank execution rate, with the difference for the counterparty's account. Follow the contract terms.

## Steps
1. Get the bank wire confirmation with the executed rate, the foreign amount, and the settled base amount. Verify: the bank's arithmetic is fully visible
2. Recompute the ERP entry at the bank rate and quantify the exact difference. Verify: the difference equals the unapplied penny amount
3. Confirm the invoice or obligation the wire settles and its expected settlement amount. Verify: after correction the payment will apply in full with no residual
4. Adjust the entry to the bank rate with the difference posted to the FX gain loss account, referencing the wire confirmation. Verify: the payment applies fully and the FX amount equals the recomputed difference
5. Change the wire booking step to capture the execution rate from the confirmation instead of the daily table rate. Verify: the next wire books at its confirmation rate

## Variant phrasings
### bank wire rate differs ERP rate penny unapplied
The two-rates phrasing.
### wire conversion rate difference small FX adjustment
When posting the correcting difference.

Compatibility: Incoming and outgoing wire booking in multi-currency AP and AR on NetSuite, SAP, Dynamics, and Sage.

## Why it happens
Two rates exist for every wire: the reference rate tables publish, and the execution rate the bank actually applies, which includes its spread and the moment of execution. Books built from the reference rate will always differ slightly from cash built from the execution rate. The difference is economically a cost of conversion, belonging in FX, and the payment stays unapplied only because systems demand exact amount equality to apply cash.

## Edge cases / pitfalls
- Execution rates on card and processor conversions diverge far more than wire rates. The same prove-and-adjust method scales, with thresholds.
- If the ERP supports booking at the payment rate, lock the rate source per payment method so wires stop inheriting the table rate.
- Repeated penny adjustments for one counterparty may signal the counterparty invoices at a rate they choose. That becomes a commercial term to settle, not endless pennies.

## Provenance

Resolved from the public thread: https://vectle.com/posts/pst_m9YBXcD-B_Zgko7BuqmNWA