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The work was priced in one currency and paid in another. The difference is a balance, not a mystery.

The invoice said one number, the client says they paid in full, and your account shows less. Nobody may be lying. Between the agreed amount and your bank sit three quiet machines: the exchange rate on the day, the rate the payment service actually applied, and the fees taken along the way. Any of them can shave a payment, and together they can shave a lot. This page gives you the order that settles it without accusing anyone: rebuild the payment in both currencies from the records, name which cause took what, check what your agreement actually said about currency, and claim whatever is left as a plain balance owed, with the math attached so the client can check it in minutes.

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Updated November 13, 2026. First published November 13, 2026. The records quoted below are real and public, read back from the live service on November 13, 2026.

Step 1. Rebuild the payment in both currencies before you write to anyone

Do not start from the amount that landed; start from the four numbers that explain it. One: the invoice amount and the currency printed on the invoice. Two: the amount the client actually sent, in the currency they sent it, from their payment confirmation, not from their memory of it. Three: the exchange rate that was applied to the conversion, which the payment service states on the receipt or the transfer record, and the date it was applied. Four: every fee taken between their account and yours, sending fees, platform fees, and receiving fees, each as its own line. Lay the four numbers in a small table and do the subtraction in both currencies. Most short payments explain themselves at this step: the converted amount at the applied rate was already less than the invoice, or the fees took the rest. The table matters because it converts an awkward feeling, I think I was underpaid, into a checkable statement a finance contact can verify against their own records in one pass.

Step 2. Sort the shortfall into its three causes, because each has a different owner

Cause one is the rate: the client converted at a retail rate worse than the market rate you looked up, so the same effort bought fewer units of your currency. Cause two is the route: banks and platforms took named fees out of the transfer, so the client sent the right value and the road kept some. Cause three is the simplest and the most common: the client paid the invoice number in their own currency, treating 1,000 of theirs as if it settled 1,000 of yours. That is not full payment under any reading; it is a payment of a different amount that happens to share the digits. Name the cause in your own notes before you write. A rate difference is a negotiation about whose rate governs. A route fee is a question about what the agreement said on fees. A wrong-currency payment of the bare number is not a disagreement at all, just an arithmetic gap, and it should be presented that way: calmly, as a balance, with the conversion shown.

Step 3. Anchor the claim to the agreed amount on the job record

The argument to avoid is two people trading exchange rates from memory. The agreed amount is a fact that was fixed before the payment existed, and it lives best on the record of the job itself. The record format is AER-1, published as an IETF Internet-Draft (draft-zambo-aer1-26), and each step carries a verifiable receipt: a receipt proves the saved result was not changed since it was saved. The two public records below show the shape of an agreed job with its decision state, the anchor your currency claim hangs from:

Accepted: the decision is on the record

Pending: checked, and still waiting on a decision

Read the accepted record as the template: the work, its steps checked, the decision made by the client on a stated date, release ok_to_release. When a job closes like that at an agreed amount in a stated currency, the payment conversation is no longer about what the job was worth; it is only about whether the money that arrived equals that amount in that currency. The pending record shows the weaker position: work checked, no decision recorded yet, release on hold. Settle the acceptance and the amount first, in writing, and a later conversion gap has something solid to be measured against.

Step 4. Claim the shortfall as a balance still owed, with the math attached

Write one short message and attach the table from step 1. It needs five lines: the invoice amount and currency; what the client sent and in which currency; the rate and fees that were applied, as lines; the amount that reached you; and the difference, stated as the balance remaining on the invoice, with a date you would like it settled by and the cleanest way to send it. Ask for the top-up in the invoice currency, by a route where the amount sent is the amount that arrives, or with the sender covering the transfer fees. Keep the tone bookkeeping, not wounded: shortfalls like this are usually a process outcome at the client, a payment run that converts at whatever rate the bank offers, not a decision to underpay you. If the agreement named the invoice currency as the amount owed, your position is plain: conversion is the payer's side of the job. If the agreement was silent, say so honestly and split the difference only as a one-time, written exception if the relationship is worth it, because a silent agreement argued once becomes the precedent for every payment after it.

Step 5. Set the next invoice up so conversion cannot shrink it quietly

Four lines on the next agreement or invoice close this whole category. First, the amount line: prices and invoices are in your named currency, and the amount owed is that figure in that currency. Second, the fees line: transfer and conversion costs sit with the sender, so the invoiced amount is the amount that must arrive. Third, the rate line, for any job you agree to price in the client's currency instead: the rate source and the date it is read, named in advance, so there is exactly one rate the conversion can be checked against. Fourth, the route: one agreed payment route whose fee behaviour you both know, instead of a fresh improvisation each run. None of this needs a lawyer or a new system. It needs the four lines written before the work starts, while everyone is friendly, which is the only moment they are cheap.

What this page cannot settle

This page cannot tell you what a court in either country would do with a silent agreement and a disputed conversion; cross-border payment disputes turn on the contract wording and the places involved, and this is general information, not legal advice. It also cannot recover a shortfall the client flatly refuses to top up on a small invoice, where the honest options are the formal routes in proportion to the amount, or pricing the lesson into the next job. A verifiable receipt proves the saved result was not changed since it was saved; it does not set an exchange rate or prove what a bank charged. What the record settles is the starting point every conversion argument needs: the amount that was agreed, in its currency, for work that was delivered and accepted.

Frequently asked questions

My client paid in a different currency and the amount came up short. What do I do?

Rebuild the payment before you dispute it. Get the four numbers: the invoice amount and its currency, what the client sent and in which currency, the exchange rate that was applied and its date, and every fee taken on the way. Sort the gap into its cause: a worse rate than you expected, fees taken by the route, or the client paying the invoice number in their own currency, which is a different amount that shares the digits. Then send one short message with the math in a small table and the difference stated as the balance remaining on the invoice, asking for the top-up in the invoice currency by a date, through a route where the amount sent is the amount that arrives. If your agreement named the currency of the amount owed, conversion sits on the payer's side. If it was silent, settle this one in writing and put the currency, fees, and rate lines on the next agreement, because a silent deal argued once becomes the precedent.

My client says they paid the full amount. Are they wrong?

They may be right about what left their account and wrong about what settled the invoice, and both can be true at once. A client who sent the full figure converted at their bank's retail rate, less transfer fees, sent everything they intended to send; what arrived is still less than the invoiced amount in the invoiced currency. The way through is to stop debating intentions and put both records side by side: their send confirmation, your receive statement, the applied rate, and the fee lines. Where the missing amount sits becomes visible, and the remaining question is the narrow one your agreement answers or fails to answer: whose side of the payment bears conversion and fees. Argue that one question, with the table attached, not the client's honesty.

Which exchange rate should the conversion be checked against?

The one your agreement names, and if it names none, there is no single correct rate, which is exactly the gap to close for next time. Payment services apply their own retail rate, usually worse than the headline market rate, and the difference on a large invoice can exceed the transfer fees. For the current payment, the honest check is the rate actually applied on the transfer record against the market rate that day: it shows whether the gap is ordinary spread or something that went wrong. For the next agreement, name the source and the reading date in advance, or simpler, price in your own currency and let the conversion happen entirely on the payer's side, so the rate stops being a shared argument at all.

Can I just add the shortfall to the next invoice?

You can invoice a documented balance, and that is cleaner than quietly inflating the next job's price. Send the shortfall as its own line with its own short statement: balance remaining on the earlier invoice after conversion and fees, with the table that proves it, dated and referenced to the original invoice number. Quietly loading it onto new work corrupts the new job's price, breaks the link between the amount and its reason, and hands the client a fair complaint if they spot it. A named balance line, agreed or disputed openly, keeps each job's money attached to its own record, which is the habit that makes every later payment argument shorter.

How does a job record help when a payment crosses currencies?

It fixes the number the conversion is measured against. When the work runs through Zambo, every job lands on its own record with a verifiable receipt for each step under AER-1, published as IETF Internet-Draft draft-zambo-aer1-26, the client accepts on that record, and the acceptance view shows status, decider, date, and release state, so the agreed amount for delivered, accepted work is a link both sides can open, in the currency the job was priced in. Every tool free once a day, plus 3 continue calls. One free wrap-up handover per day, and pickup is always free. For $0.99, run your next cross-border job on one record with the invoice currency named in the agreement, so if a payment ever lands short, the balance is arithmetic against a checkable amount, not a debate about what was agreed: get the Day Pass. A Day Pass is unlimited for 24 hours, no subscription. Ongoing use is the Zambo Pass at $29 a month, $19 a month for $ZAMBO holders, or Lifetime at $250 one time.

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