How to Check Whether a Supplier Invoice Matches the Contract

Team Svenry

4 days ago

4 min read

A supplier invoice should not only be checked for the correct amount and required invoice information. It should also match the agreement behind the purchase.

This is particularly important for organizations with large supplier bases, recurring services, and complex contracts. A contract may include agreed prices, volume discounts, index adjustments, additional fees, payment terms, and specific conditions for when costs can be charged.

The key question is:

Does the invoice reflect what was actually agreed in the contract?

Start With the Contract, Not the Invoice

An invoice shows what the supplier wants to be paid. The contract shows what the organization has agreed to pay. A proper invoice review should therefore compare relevant invoice information with the applicable contract terms, including:

Agreed prices
Quantities and volumes
Discounts
Additional fees
Billing periods
Contract duration
Index adjustments
Payment terms
Products or services covered by the agreement

An invoice can be formally correct and still violate the commercial terms of the contract.

Verify the Supplier

The first step is to make sure the invoice actually comes from the supplier that holds the contract. Organizations should compare information such as the supplier's legal name, registration number, VAT information, and other identifiers against their supplier records and contract.

This is especially important when supplier information changes over time. For Swedish organizations, Skatteverket provides guidance on invoice requirements and the information that should normally be included on an invoice, such as seller and buyer information, VAT details, invoice number, and information about the goods or services supplied.

However, meeting formal invoice requirements does not mean that the invoice necessarily complies with the underlying contract.

Does the Price Match the Agreement?

One of the most important checks is whether the invoiced price corresponds with the agreed price. For example, if a contract specifies an hourly rate of SEK 1,200, the invoice should be checked against that rate. The same applies to fixed monthly fees, unit prices, service charges, and other cost components.

Contracts may also allow prices to change through indexation. In these cases, the organization should verify that the correct index, period, and calculation method have been used. For organizations processing large numbers of invoices, manually performing these checks can quickly become time consuming.

Does the Quantity Match What Was Ordered?

Price is only one part of the calculation. An invoice may use the correct unit price but still contain an incorrect quantity.

For example:

100 hours × SEK 1,000 = SEK 100,000

If the supplier invoices 120 hours, the organization needs to determine whether the additional 20 hours were actually delivered and whether they were covered by the agreement. The same principle applies to products, consulting services, subscriptions, transportation, maintenance, and other recurring costs.

Check Additional Charges

Supplier invoices often contain more than the agreed base price.

Additional charges may include:

Administration fees
Freight
Travel expenses
Service charges
Additional services
Index adjustments
Overtime
Material costs

The important question is not simply whether the charge appears on the invoice.

It is whether the contract allows the supplier to charge it.

Three-Way Matching Is Useful, But Not Always Enough

Many finance teams use three-way matching:

Purchase Order → Delivery → Invoice

This is an effective control for checking whether an invoice corresponds to an order and whether the goods or services were delivered. However, three-way matching does not necessarily confirm that the invoice complies with the underlying contract.

A purchase order may already contain an incorrect price. A supplier may also continue invoicing according to outdated terms after a contract has been amended. This is why organizations may also need to compare invoices against the current contract and current supplier information.

Invoice Verification Is Also Fraud Prevention

Contract compliance is not only about identifying overcharges. It can also help detect fraud.

A fraudster may attempt to:

Invoice for services that were never ordered
Impersonate an existing supplier
Change payment information
Continue invoicing after a contract has expired
Manipulate prices or quantities
Create a supplier that resembles an existing company

This means invoice verification should be combined with counterparty verification.

Monitor Suppliers Throughout the Contract

A supplier should not necessarily be checked only when the contract is signed.

Supplier information and risk can change during the relationship. Organizations may need to monitor changes involving company status, ownership, insolvency, sanctions, banking information, and other relevant risk indicators.

This is particularly important for long-term contracts where the same supplier may invoice the organization for several years.

The question is not only:

Was this supplier legitimate when the contract was signed?

It is also:

Is the supplier still legitimate when the next invoice arrives?

How Svenry Can Help

Svenry helps organizations combine invoice information with supplier and counterparty intelligence. By checking counterparties against relevant external data sources and risk indicators, organizations can identify invoices and supplier relationships that require additional attention.

This can include identifying: