Managing Duplicate Documents in Dost

Managing Duplicate Documents

(If you want a conceptual overview of anti-duplicate configuration, you can review the article Advanced Document Options (Other tab).)

In this section, you will learn how to handle the two most common duplicate-related situations: when Dost marks a document as a duplicate even though it is not (false positive), and when a real duplicate is not detected (false negative).

How Does Dost Detect Duplicates?

Dost detects duplicates by comparing key document fields. By default, the comparison is based on the invoice number and the supplier VAT ID. If two documents share the same values in these fields, Dost considers them duplicates.

The fields used for comparison are configured in Settings > Document > “Other” tab (Advanced Document Options (Other tab)). If you need to expand or modify the detection fields, refer to that section.

When Dost Incorrectly Marks a Document as a Duplicate (False Positive)

Why does this happen?

• The same supplier issues invoices with the same number in different periods (for example, invoice numbers that reset annually).
• Two different invoices have very similar data (same amount, same date, same supplier) but represent different transactions.
• The invoice number extraction is incorrect, causing the extracted value to match another document accidentally.

How do I fix it? (Steps)

1. Open the document marked as duplicate. You will see the Duplicate status in the list.
2. Review the document and confirm that it is indeed different from the other one.
3. Manually change the status from Duplicate to Need Review or the appropriate status so it can continue through the workflow.

If this false positive occurs repeatedly with the same supplier, review the detection field configuration in the Other tab and consider adding additional fields (for example, date) to reduce false matches.

💡 If the issue is caused by incorrect invoice number extraction (leading to unintended matches), address it first using self-training or a mapping rule (see Extraction Errors).

When Dost Fails to Detect a Real Duplicate (False Negative)

Why does this happen?

• The same invoice was submitted twice, but the invoice number was extracted differently in each case (for example, with or without leading zeros).
• The configured duplicate detection fields are not sufficient to cover that specific case.
• The second invoice arrived through a different channel (email + manual upload) and has different metadata.

How do I fix it? (Steps)

1. Identify the two duplicate invoices in the Documents section.
2. Compare their key fields to understand why Dost did not match them.
3. Delete or manually mark one of the documents as duplicate so it is not processed.
4. To prevent future cases, review the duplicate detection configuration in Settings > Document > “Other” tab and add additional fields if needed.

Best Practices

• Anti-duplicate configuration is a balance: too many comparison fields can cause false negatives, while too few can cause false positives. Adjust it based on your supplier patterns.
• Regularly review documents in Duplicate status to ensure they are real duplicates and not false positives blocking the workflow.
• If you receive many invoices by email, ensure suppliers do not resend the same invoice multiple times. Clear communication helps reduce the issue at the source.
• Define an internal policy for duplicate handling: who is responsible for resolving false positives and updating document statuses.