# How to stop paying a vendor invoice twice in Sage 300

Before you enter an A/P invoice in Sage 300, search the vendor's bills for the same number or amount. Use one reference format and check the payment batch for repeats.

Duplicate payment is when the same supplier invoice is entered or paid more than once. It often happens when an invoice arrives by two routes.

## Before you start

- A/P Options access

## The Sage 300 way

Where to find it: Accounts Payable > A/P Setup > Vendor Groups / Vendors

1. On the vendor group (and vendor) choose whether to check for duplicate invoices.
2. The check can use same vendor and amount, or same vendor and date.
3. You cannot make a change that would create duplicate document numbers for the same vendor.

## Limits in Sage 300

- The check is vendor with amount or date, not an exact invoice number test across vendors.

## The Pulsify way

1. Forward the supplier's invoice to Pulsify.
2. Pulsify compares the invoice number with punctuation and case ignored, plus the same vendor, invoice date or tax ID.
3. It checks other Pulsify documents and active bills in Sage 300.
4. A possible duplicate is flagged. Open the match, then reject or approve anyway.

Pulsify connects to Sage 300. We set up the connection for you.

What Pulsify does not do here:

- Pulsify flags. You decide.
- A duplicate with a quite different invoice number may not be found.

## Common mistakes

- Leaving the duplicate check off on the vendor group.
- Relying on it for an invoice that was re-keyed with a different date and amount.

## Common questions

### How does Sage 300 check for duplicates?

On the vendor group and the vendor you choose whether to check. The check can use same vendor and amount, or same vendor and date.

### Can I enter the same document number twice for one vendor?

No. You cannot make a change that would create duplicate document numbers for the same vendor.

### Does it check across vendors?

No. The check is vendor with amount or date, not an exact invoice number test across vendors.

### What does Pulsify check?

The invoice number with punctuation and case ignored, plus the same supplier, invoice date or tax ID.

## Sources

- https://cdn.na.sage.com/docs/en/customer/300erp/2023/open/Sage300_AccountsPayable_UserGuide.pdf

### Also confirmed by

- Greytrix Sage partner blog, 2018: https://www.greytrix.com/blogs/sageaccpacerp/2018/03/12/prevent-duplicate-invoices-in-accounts-payable/

Source: https://www.pulsify.tech/how-to/stop-paying-a-bill-twice-in-sage-300/ (last checked 2026-10-19)