Payhawk Receipts Not Matching: Fix the Mailbox Handoff

Trace the current destination, configured sender, DKIM or SPF, forwarding rule, attachment limits, Pending request, and wrong-match recovery without creating duplicates.

By ilios Galil · Founder, Expensent

Updated August 3, 2026

Last verified : August 3, 2026

Read this if…

Use this guide after a receipt or invoice was supposed to reach Payhawk but failed processing, stayed Pending, or attached to the wrong expense. For initial setup and capture-method selection, use the main Payhawk guide.

Related: Open the Payhawk setup guide

TL;DR

Start with the Payhawk response and Mailbox request state. An error, Pending item, and wrong match require different fixes.

Compare one direct send with one rule-based send. If direct works and the rule does not, check the forwarding path, DKIM, SPF, and tenant configuration.

Process an existing Pending request or move a wrong attachment in Payhawk. Do not repeatedly resend a document Payhawk already retained.

1. Identify the Payhawk state

Start with the source email thread and Payhawk Inbox. A Payhawk error points to a sender or document check, Pending means the document needs manual association, and a success response links to the result Payhawk created or matched.

This distinction prevents duplicate sends and directs the reader to the right fix.

Observed state
Observed stateWhat it provesNext action
No sent messageThe source workflow did not sendCheck the Expensent action or mailbox rule before troubleshooting Payhawk
Payhawk error responseThe Mailbox received a message but rejected or could not process itUse the exact error reason to fix sender authentication, size, count, or format
Pending Mailbox requestPayhawk has the document but needs a manual decisionAttach it to the correct existing expense or create the correct new expense
Success, wrong expenseProcessing and association occurred, but the result is wrongMove the document to the verified target through the web portal
Success, correct expenseThe Mailbox path worked for this exampleReview fields and downstream workflow before expanding automation

2. Check the destination and sender

Open Group dashboard > Settings > Mailbox and compare the live company-generated destination with the failed message. Do not infer the address from the company name or rely on a legacy paid or unpaid address unless the account still uses it.

Confirm that Payhawk is configured for the actual sending address, especially when aliases, distribution lists, gateways, or forwarding services can rewrite the sender.

Do not debug a stale address

Current Payhawk help describes a group-level company Mailbox. Verify the live destination before spending time on attachment, OCR, or matching theories.

3. Open the response and Mailbox request

Payhawk replies in the submitted email thread. In Payhawk, filter Inbox by Request type > Mailbox requests and match the request timestamp to the source message.

A Pending request retains the document for a manual decision. Open it instead of sending another copy.

4. Test sender authentication and forwarding

Payhawk documents DKIM and SPF failures as Mailbox rejection reasons. Preserve the error and ask the mail administrator to inspect the domain, authentication results, and any gateway that changes the sender.

Compare one direct send from the configured mailbox with the normal Gmail or Outlook rule. If direct delivery works, fix the forwarding rule or mail policy rather than changing the receipt.

5. Fix document count, size, or format

Payhawk currently limits a Mailbox message to 40 attachments, 20 MB combined, and less than 10 MB per file. Split oversized packages or use the Payhawk portal.

Use a supported PDF, PNG, JPG, or JPEG file, and remove password protection before submission. When the receipt lives in the email body, confirm that the body contains the actual evidence rather than only a portal link.

6. Attach a Pending document

Open the Pending Mailbox request, choose Attach to expense, select the correct entity, and either create a new expense or attach the document to an existing one.

Compare the source with the entity, owner, supplier, amount, date, currency, and payment method. Payhawk controls the association; an Expensent sending record can confirm the source mailbox, destination, and time.

7. Move a document to the right expense

If Payhawk attached the document to the wrong expense, verify the intended entity, owner, transaction, supplier, amount, date, and currency from the original source.

Use Move to another expense in the Payhawk web portal, then inspect both records. Correct the existing association instead of resending the email.

8. Sources checked

These sources were used to verify product behavior, current terminology, and the boundaries between native workflows and Expensent.

10. Frequently asked questions

Why did my emailed receipt not match in Payhawk?

First determine whether Payhawk processed the message. A sender or attachment error means intake failed. A Pending Mailbox request means the document was processed but needs manual association or expense creation. A wrong attachment means matching completed incorrectly and the document should be moved through the supported Payhawk workflow.

Where do unmatched Payhawk Mailbox documents appear?

Payhawk says an unmatched document can be sent to the Pending tab of the Inbox. Open the Mailbox request, select Attach to expense, choose the entity, and either attach it to an existing expense or create a new expense with the correct payment method.

How do I know whether the forwarding rule or Payhawk is the problem?

Send one message directly from the configured source address and send the same controlled test through the forwarding rule. If the direct message creates a Payhawk record but the rule does not, Payhawk recommends checking the rule and asking internal IT to review DKIM, SPF, and mailbox configuration.

What Payhawk Mailbox attachment limits can cause rejection?

Current error documentation rejects messages with more than 40 attachments, a combined attachment size above 20 MB, or a single file of 10 MB or more. Unsupported, corrupt, or password-protected files can also fail. Older Payhawk pages may show different limits, so use the current error page.

What should I do if Payhawk attached the receipt to the wrong expense?

Payhawk documents a Move to another expense option in the web portal. Preserve the source email, verify the correct target transaction, move the document through the supported interface, and confirm the result before deleting or resending anything.

Should I resend a receipt that is already Pending?

Usually no. A Pending request means Payhawk already has the document. Process the existing request or attach it manually. Repeated sends can create duplicate evidence and make it harder to identify the original path.

Can Expensent fix Payhawk matching?

Expensent preserves the source email, destination, and sending record for each routed document. Payhawk continues with security checks, processing, entity identification, matching, bill creation, and manual association.

Find the source behind a Payhawk exception

Expensent connects each routed document to its source email and Payhawk destination, so you can recover the handoff before resolving the record in Payhawk.

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Guide slug: payhawk-receipts-not-matching