Invoice validation: the checks to run before you post an invoice
For accounts payable (AP) teams and controllers. See the checks an invoice must pass before you post it, follow one invoice through them, and learn who fixes each failed check.
Key takeaways
- Invoice validation checks each invoice before you post it to the ledger. It compares the invoice with your vendor master, your earlier invoices, the purchase order and the receiving record.
- Run the quick checks first. An unknown vendor or a duplicate should stop an invoice before anyone matches its lines to a PO.
- An invoice can add up and still be wrong. Check each line, and check that tax is charged only on taxable items.
- When an invoice fails a check, it goes on hold as an exception until someone fixes the cause. A sponsored analyst report from Ardent Partners puts the average invoice exception rate at 18.4%.
- In AP, invoice reconciliation usually means matching invoices with orders and receiving records. Checking a vendor's statement against your ledger is a separate month-end job.
On this page
Invoice validation checks each invoice against your own records before accounts payable (AP) posts it to the ledger. The checks confirm that the vendor is on file and the invoice isn't a duplicate. They also recheck the math and tax, and match the charges to the purchase order (PO) and the receiving record. An invoice that fails any check stays on hold until someone fixes it.
Many teams call the same work invoice verification.
The checks, in the order to run them#
Each check compares the invoice with a record you already trust. The vendor master, for example, is your list of approved vendors and their details.
| Check | Compared with | Common failure |
|---|---|---|
| Vendor | Your vendor master: name, remit-to address, tax ID and payment terms | The vendor isn't set up yet, or the remit-to address has changed |
| Duplicate | Invoices already received from the same vendor | The same invoice arrives twice, by email and again on paper |
| Header fields | Your invoice policy and the vendor record | No PO number, the wrong bill-to company, or terms that differ from the vendor record |
| Math | The invoice's own lines and totals | A line where quantity × unit price isn't the amount, or a total that leaves out freight |
| Tax | The rate for the ship-to address, and which items are taxable | The wrong rate, or tax on an item that isn't taxable |
| PO and receipt | The purchase order and the receiving record | A price above the PO price, or more units billed than were received |
Start with the vendor and duplicate checks. They're quick, and if either one fails, you can hold the invoice right away. There's no point matching every line to a PO if the invoice is a copy of one you already have. Leave PO matching for last, because it needs records from purchasing and receiving.
Matching also needs tolerances, which are the small differences you accept without a hold. 2-way vs 3-way matching explains how to set them.
One invoice through the checks#
Take invoice NKE-9921 below. Northeast Kitchen Equipment billed Harbor Street Bakery LLC for bakery equipment and its installation. The invoice runs to 2 pages and 11 lines, with a total due of 24,650.00.
| Field | Extracted value | Read |
|---|---|---|
| Vendor name | Northeast Kitchen Equipment | |
| Invoice number | NKE-9921 | |
| Invoice date | 2026-08-12 | |
| Due date | 2026-09-11 | |
| Payment terms | Net 30 | |
| PO number | 5498 (handwritten) |
| Field | Extracted value | Read |
|---|---|---|
| Vendor address | 37 Bridge St, Westbrook, ME | |
| Bill to | Harbor Street Bakery LLC | |
| Ship to | 22 Thames St, Portland, ME | |
| Remit to | PO Box 3170, Portland, ME |
| Field | Extracted value | Read |
|---|---|---|
| Item code | WT-3072 | |
| Description | Stainless work table, 30 x 72 in | |
| Quantity | 2 | |
| Unit of measure | EA | |
| Unit price | 385.00 | |
| Amount | 770.00 |
| Field | Extracted value | Read |
|---|---|---|
| Subtotal | 23,250.00 | |
| Sales tax rate | 5.5% | |
| Sales tax | 1,278.75 | |
| Freight | 121.25 | |
| Total due | 24,650.00 |
The vendor check comes first. Northeast Kitchen Equipment has to be in your vendor master. The remit-to address, where you send payment, is PO Box 3170 in Portland, Maine. It has to match the address on file. Next comes the duplicate check. Search for an earlier NKE-9921 from this vendor. Also search by amount and date, because a vendor may send the same invoice again with a new number. Duplicate invoice detection explains the rules for spotting a duplicate.
Then the math. On each line, quantity times unit price should equal the amount. Line 4, for example, is 2 work tables at 385.00 each, which makes 770.00. The 7 lines on page 1 add up to 21,607.00, and the 4 lines on page 2 add up to 1,643.00. Together they make the 23,250.00 subtotal. Check every line, not only the total. A line's amount can be wrong even when all the lines add up to the subtotal.
The totals add up as printed. The invoice charges 5.5% sales tax on the 23,250.00 subtotal, so the tax is 1,278.75. With 121.25 for freight, the total due is 24,650.00. The goods ship to Portland in Maine, where the general sales tax rate is 5.5%.
The tax check still fails. Line 11, on page 2, is a separate charge of 650.00 for installation and start-up. Maine law leaves installation charges out of the taxable price when they're billed separately. So the tax should be 5.5% of the other 22,600.00, which is 1,243.00. The invoice overcharges 35.75, and the correct total due is 24,614.25. AP holds the invoice and asks the vendor for a corrected one. If anyone is unsure of the rule, the tax team decides.
Keep going with the other checks while the invoice is on hold, so one corrected invoice can fix everything. The terms are Net 30. Thirty days after the August 12 invoice date is September 11, which is the due date on the invoice.
The PO check needs records from outside the invoice. The PO number, 5498, is handwritten, so confirm it before you match anything to it. Then compare each of the 11 lines with PO 5498 and the receiving record, on quantity, unit price and amount.
Our take. Reading NKE-9921 correctly is only the first part of the job. What Harbor Street Bakery should pay depends on records outside the invoice. Those are PO 5498, the receiving record, the vendor master and the invoices already received. We'd judge a validation tool by how many of those records it checks the invoice against before a person sees it. How well it reads one page matters less.
When an invoice fails a check#
A failed check doesn't mean the invoice is rejected. The invoice goes on hold as an exception until someone fixes the cause. Oracle Payables works this way. In Oracle, you can't pay an invoice or create its accounting entries until the invoice is validated. Oracle also puts an invoice on hold when it finds an exception. In one of Oracle's examples, an invoice bills 6 units when only 5 were received. The hold stays until the receiving team records the last unit and someone runs validation again.
Exceptions are common. Ardent Partners' State of ePayables 2025, a sponsored analyst report, puts the average invoice exception rate at 18.4%. The 20% of AP teams that process invoices at the lowest cost and in the least time have exception rates 47% lower than the rest. Each kind of failure has its own fix and its own owner.
Which check did the invoice fail?
Validation, verification, matching and reconciliation#
These four words overlap, and teams use them loosely. Validation and verification usually mean the same checks. You run them before you post an invoice. Oracle Payables calls the step validation, and many AP teams call it verification.
Matching is one of those checks. It compares the invoice with the PO, which is 2-way matching. It can also compare the invoice with the PO and the receiving record, which is 3-way matching.
Reconciliation compares two sets of records and explains the differences. In AP, invoice reconciliation usually means matching invoices with orders and receiving records, then clearing what doesn't agree. SAP Ariba uses the term this way. At month end, reconciliation can also mean checking a vendor's statement against your AP ledger, which is a separate job. Docsumo matches vendor statements to the ledger too.
Automating invoice validation#
Every check depends on reading the invoice correctly first, and invoice data extraction covers that step. After that, software can run every check on every invoice as it arrives. People then see only the invoices that fail, with the reason attached.
Checked by hand
- A clerk keys the invoice, then rechecks the totals on a calculator
- Someone searches for duplicates when there's time
- The PO and the receiving record sit in other screens and inboxes
- Exceptions wait in email until someone follows up
Checked by software
- Fields and every line item are read from the PDF or scan
- The math is rechecked on every line
- Every invoice is checked for duplicates when it arrives
- Only failed invoices reach a person, with the reason
Docsumo, our product, is an intelligent document processing (IDP) platform. Invoices reach it by email, upload or API. It extracts the header fields and every line item of an invoice, and it joins tables that run across pages. You set a confidence threshold for each field, which is how sure Docsumo must be about a value. A field below its threshold goes to a person. When that person clicks the field, Docsumo highlights the line on the invoice where the value came from. Docsumo flags invoices that duplicate one already received. Checks such as recalculating each line and the tax are steps you set up in the Docsumo workflow.
On the Enterprise plan, Docsumo looks up extracted values in your master data, such as your vendor list. Also on the Enterprise plan, its cross-document checks match each invoice line to the PO and the receiving record on quantity, unit price and amount. On the Business plan, it routes invoices for approval by the rules you set. The data goes to your ERP through the API and webhooks. Docsumo doesn't create POs or pay vendors. The invoice processing software page shows each step from inbox to ERP, and accounts payable automation covers matching. Plans are on the pricing page.
- 99%field-level accuracy on 250+ document types
- 95%+straight-through processing
- 99%+touchless invoices at Valtatech
Which check to automate first#
Count last month's holds and group them by the check that caused each one. Start with the check that caused the most holds. If it's the vendor check, clean up the vendor master before you automate anything. If it's PO matching, make sure the receiving team records deliveries on time. If a delivery is recorded late, the software will hold the invoice for goods that have already arrived.
Book a demo with a month of your own invoices, exceptions included, or start a free trial.
Frequently asked questions#
How do you validate an invoice?
Check that the vendor is in your vendor master and that the invoice isn't a duplicate. Then recheck each line, the totals and the tax. Last, match the lines to the purchase order and, for goods, the receiving record. Anything that fails goes on hold for the person who can fix it.
What is the invoice validation process?
It's the step between receiving an invoice and posting it to the ledger. The invoice goes through a set of checks, and if it fails any check, it goes on hold as an exception. In Oracle Payables, for example, you can't pay an invoice or create its accounting entries until it's validated.
How do you check if an invoice is valid?
A valid invoice comes from a vendor on file and hasn't been received before. On each line, quantity times unit price equals the amount, and the totals add up. Tax is charged at the right rate, and only on taxable items. The invoice shows the PO number and payment terms you expect. It also matches the PO and the receiving record within your tolerances, which are the small differences you accept.
What is the difference between invoice validation and invoice reconciliation?
Validation checks one invoice before you post it to the ledger. Reconciliation compares two sets of records and explains the differences. In AP, invoice reconciliation usually means matching invoices with orders and receiving records. At month end, it can also mean checking a vendor's statement against your ledger.
What does invoice validation software do?
In general, it reads each invoice, runs the checks and sends only the failures to a person. Docsumo, our product, extracts the fields and line items and flags duplicate invoices. On the Enterprise plan, it also looks up vendors in your master data and matches invoice lines to the PO and receiving record.
Sources
- Ardent Partners (Payables Place): State of ePayables, Part Nine, AP benchmarks and Best-in-Class performance (sponsored analyst report, Jan 2026)
- Oracle Fusion Cloud Financials 25D, Using Payables Invoice to Pay: How invoices are validated
- SAP Learning: Invoice reconciliation (SAP Ariba course)
- Maine Revised Statutes, Title 36, §1752(14): definition of sale price (installation charges, if separately stated, excluded)
- Maine Revenue Services: Instructional Bulletin No. 39, Sale price upon which tax is based (last revised Mar 11, 2026)
- Maine Revenue Services: Sales tax rates and due dates
First published .