Find the exact invoice and its earlier handover
Look for the original invoice number in the new document. Use it to find the original PDF, then check the supplier and the business the invoice was issued to. Similar attachment names or the same supplier alone do not establish that the documents belong together.
Next, trace the handover to your accountant. Check the sent email to confirm that the original invoice was actually attached. For a shared folder, note its name and the date you sent the link. A sent message shows what you handed over; on its own, it does not tell you whether your accountant received or processed the document.
Save the new PDF alongside the original without overwriting it. Keep the supplier’s message too if it explains the change. If the new document does not refer to the original invoice and you cannot verify the connection, ask the supplier to clarify. Meanwhile, you can tell your accountant that a new document has arrived and you are checking which invoice it relates to.
Prepare the two documents with a brief explanation
In this fictional example, Company Alfa sent its accountant supplier Beta’s invoice F-2026-184 in an email on 3 September. On 17 September, the same supplier sent credit note D-2026-027, explicitly referring to that invoice. The names, numbers and dates are invented.
A short overview shows your accountant which document they already had and which one is new. Copy the numbers for your own message from the documents and the handover date from the sent email. Filenames are only a way to help identify the files.
| What you are sending | Identification in the fictional example | What your accountant needs to know |
|---|---|---|
| Original invoice | Beta, F-2026-184, customer Company Alfa | Included in the handover on 3 September. |
| Newly received credit note | Beta, D-2026-027; refers to F-2026-184 | Arrived on 17 September; you are sending it now as an addition. |
| Supplier’s explanation | The message sent with the credit note | Include it if it explains the change or the connection between the documents. |
If your accountant can easily access the original invoice, send the new credit note with an exact reference to the earlier handover. Otherwise, attach the original PDF too and describe it as a copy of a document already sent. You do not need to resend the entire original package.
If the supplier sent a new PDF with the same invoice number instead of a separate credit note, keep both versions and explain what changed according to their message. Use the label and number on the document you received; do not create your own corrective document.
Explain what your accountant already had and what is new
In the covering message, give both document numbers, the business and the location of the original handover. The template below assumes you are attaching the original invoice again. Fill in the actual details and adjust the attachment description to match what you are sending.
Select the text, copy it into an email and fill in the details in square brackets.
If you cannot trace the original handover, replace both references to having sent it earlier with: “I have not confirmed whether you already have the original invoice from me; I am attaching it for context.” If you are not resending the original PDF, replace the attachment sentence with an exact reference to where your accountant can find it.
State separately what you know about a refund
A credit note does not, by itself, confirm that the supplier has already refunded you. Nor does an incoming payment necessarily identify the document it relates to. Alongside the new document, describe separately what you know about payment or a refund.
If the refund appears in your bank record and your accountant needs that record, send it through the agreed channel. State which pair of documents it relates to according to the information available, or say that the connection is still unclear. If the supplier has only announced a refund, you can write: “The supplier has announced a refund; I have not yet confirmed receipt of the money.”
Leave the supplier’s PDFs unchanged and do not combine the amounts into your own “final invoice”. Your accountant receives the original document, the newly received document and an explanation of their connection; they assess how to process them and handle any payment reconciliation.