A duplicate invoice check stops the same supplier bill being entered and paid twice.
What Sage 300 does on its own
Accounts Payable can check for duplicate invoices at vendor group and vendor level. The check uses the same vendor and amount, or the same vendor and date. The system will also not let you create duplicate document numbers for the same vendor.
- Check works within one vendor only.
What you need in Sage 300
- A/P Options access
Setting it up in Sage 300
Where to find it: Accounts Payable > A/P Setup > Vendor Groups / Vendors
- Open A/P Setup > Vendor Groups.
- Choose whether to check for duplicate invoices for the group.
- Pick same vendor and amount, or same vendor and date.
- Repeat on the vendor record if one vendor needs a different setting.
- Enter invoices as normal and read any warning before you add the entry.
Good to know in Sage 300
- The check is vendor with amount or date, not an exact invoice number test across vendors.
- Two vendor records for one supplier are not compared with each other.
- You cannot make a change that would create duplicate document numbers for the same vendor.
How to do it in Sage 300
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.
What Pulsify adds
- Pulsify checks every invoice against earlier ones on invoice number plus supplier, tax ID or date.
- Bills keyed straight into Sage 300 count too.
- A file identical to one already uploaded is held. A person can process it anyway.
- A suspected duplicate asks the approver to confirm with Approve anyway.
Pulsify connects to Sage 300. We set up the connection for you. More about duplicate invoice checks in Pulsify.
What Pulsify does not do
- Pulsify never matches duplicates on amount alone.
- A duplicate flag is a warning. The approver decides.
More help
- Duplicate invoice checks for Business Central
- Duplicate invoice checks for MYOB Acumatica
- Duplicate invoice checks for Sage 200
- Invoice fraud checks for Sage 300
- Line item coding for Sage 300
- Multi-entity accounts payable for Sage 300
- All Sage 300 how-to guides
Sources
Last checked 2026-10-19.
Also confirmed by
Common questions
Does Sage 300 stop duplicate supplier invoices?
It can warn using a setting on the vendor group and vendor: same vendor and amount, or same vendor and date. It will not allow duplicate document numbers for one vendor.
Does the check compare invoice numbers?
Document numbers are blocked for the same vendor. The duplicate check option itself compares amount or date for the vendor.
Will it catch an invoice entered under two vendor records?
No. The check works within one vendor, so a supplier set up twice is not compared.
Why do duplicates happen?
The same invoice arrives by email and post, a supplier resends it as a reminder, or two people enter it. A statement can also be keyed as a bill.
Pulsify setup guides
Want this done for you?
Book a call to see how Pulsify handles duplicate invoice checks in Sage 300.