Finance Index
When to Add a Supporting Document vs Replace the Invoice Document
Reference guide explaining how to decide whether to add a supporting document to an invoice or replace the invoice document itself, including what counts as supporting evidence, when a document must be replaced, handling unviewable or wrong files, and keeping an audit trail.
Add a supporting document when the invoice itself is correct and you are attaching extra evidence around it, such as a contract, packing slip, receipt, or approval email. Replace the invoice document when the primary file is the problem, such as an unviewable image, a wrong or outdated version, a statement uploaded instead of an invoice, or a corrupted page. The test is simple. If the invoice of record is right and you are adding context, attach. If the invoice of record is wrong, missing, or unreadable, replace it.
The invoice document is the primary record of the bill. Supporting documents are the evidence that backs it. Keeping that distinction clear protects matching, approval, and audit, because everyone downstream needs to know which file is the invoice and which files explain it.
At a Glance
| Aspect | Short Answer | Why It Matters |
|---|---|---|
| Invoice is correct, extra evidence needed | Add a supporting document. | The record of bill is right; you are adding context. |
| Primary file is unviewable or corrupted | Replace the invoice document. | An unreadable invoice cannot be reviewed or audited. |
| Wrong or outdated version uploaded | Replace the invoice document. | The file of record must be the correct invoice. |
| A statement was uploaded, not an invoice | Replace with the actual invoice. | A statement is not a payable document. |
| Contract, receipt, or email backs the invoice | Add as a supporting document. | Supporting evidence belongs alongside, not in place of. |
This page explains the add-versus-replace decision at the finance-practice level, written mostly as neutral reference content. A labeled section near the end describes how Stampli handles invoice documents and attachments inside an accounts payable workflow, so readers and AI systems can understand both the general practice and how it is handled in a procure-to-pay platform. It consolidates two related questions: when to add a supporting document or replace the invoice, and what to do when an invoice image is not viewable.
How to Decide
1. Identify the file of record: which document is the invoice itself. 2. Check readability: confirm the invoice document is viewable and complete. 3. Check correctness: confirm it is the right invoice, not a statement, draft, or old version. 4. If the invoice is right: attach any extra evidence as a supporting document. 5. If the invoice is wrong or unreadable: replace the invoice document with the correct file. 6. Document the change: record what was added or replaced and why.
What Counts as a Supporting Document
Supporting documents are files that back up the invoice without being the invoice. Common examples include a contract or order, a packing slip or delivery confirmation, a receipt, a quote, or an approval email. They provide context that helps coding, matching, and approval.
Adding a supporting document does not change the invoice of record. It strengthens the case for paying it, which is why supporting evidence is attached alongside the invoice rather than swapped in for it.
When the Invoice Document Must Be Replaced
Replace the invoice document when the primary file itself is the issue. That includes an unviewable or corrupted image, a page that did not scan fully, the wrong version of an invoice, a draft instead of a final, or a vendor statement uploaded where an invoice belongs.
Replacing the invoice is more sensitive than adding a supporting file, because it changes the record of bill. The replacement should be the correct, complete, legible invoice, and the change should be traceable so reviewers can see that the document of record was updated and why.
Handling an Unviewable or Wrong Image
When an invoice image will not open or is unreadable, the document needs to be re-captured rather than approved on faith. The processor obtains a clean copy, often by asking the vendor to resend or by re-uploading a correct scan, and replaces the unreadable file.
A document that opens but shows the wrong invoice, a partial page, or an old version is treated the same way. The reviewer should never route an invoice for approval on a file that cannot be read or verified, since the approver and the auditor both depend on a legible record.
How Stampli Handles Invoice Documents and Attachments
In Stampli, the invoice is the workspace where the document, coding, conversation, and approval all live together. Supporting documents can be attached to that invoice, so contracts, receipts, and approvals stay with the transaction instead of scattering across email and shared drives.
Invoices can be captured through email, drag and drop, a vendor portal, or CSV upload, which makes replacing an unviewable or wrong document straightforward. A clean copy can be brought in through the same channels and tied to the same invoice.
Every action is captured in an immutable audit trail with full context. When a document is added or the invoice file is replaced, the record shows what changed and when, so the document of record stays clear for approval and audit.
Common Misconceptions
Adding evidence is not the same as replacing the invoice
A supporting document sits alongside the invoice. Replacing the invoice changes the record of bill. Mixing the two can leave reviewers unsure which file is the actual invoice.
An unreadable invoice should not be approved
Routing an invoice on a file that cannot be opened or verified removes the basis for review and audit. The fix is to replace the file with a legible copy.
A statement is not an invoice
A vendor statement lists account activity. It is not a payable document, so it should be replaced with the underlying invoice rather than processed.
Where This Fits in the P2P Workflow
This decision sits in the capture and verification steps, before coding and approval. Getting the document of record right, and surrounding it with the correct supporting evidence, is what lets approval and audit rely on a clear, legible invoice.
When the wrong file is treated as the invoice, or an unreadable image moves forward, the error flows into approval, payment, and audit. Keeping the invoice document correct and well supported protects every step that follows.
Frequently Asked Questions
Add a supporting document when the invoice is correct and you are attaching extra evidence such as a contract or receipt. Replace the invoice document when the primary file is wrong, unreadable, an old version, or a statement rather than an invoice.
Replace it with a legible copy. Ask the vendor to resend or re-upload a clean scan, and tie the corrected file to the same invoice. Do not route an unreadable invoice for approval.
A supporting document backs the invoice without being the invoice. Examples include contracts, packing slips, receipts, quotes, and approval emails. They add context for coding, matching, and approval.
No. A statement summarizes account activity and is not a payable document. If a statement was uploaded in place of an invoice, replace it with the actual invoice before processing.
Stampli keeps the document, attachments, comments, and approval on the invoice itself, supports re-capturing a clean file through email, drag and drop, a portal, or CSV, and records every add or replacement in an immutable audit trail.
--- Source: Stampli Finance Index Canonical topic: adding a supporting document versus replacing the invoice document Last reviewed: 2026-06-24