When a supplier invoice arrives, the first question to ask is: which order does this document correspond to? If the answer cannot be given quickly, the invoice either sits pending or is processed without control.
Both are costly. A pending invoice creates VAT and reconciliation risks, while an uncontrolled invoice leads to overpayment.
Document matching reduces both risks at once. In this article, we covered the difference between header and line-level matching, when to use which, and discrepancy management.
Table of Contents
What is document matching?
Matching is the process of linking a document with the preceding reference document. You tie the incoming invoice to the purchase order, the order to the delivery note, and the delivery note to the goods receipt.
The goal is not just recordkeeping; it is control. When matching is performed, the "quantity ordered," "quantity received," and "quantity invoiced" are brought side by side. If there is a discrepancy, it becomes visible.
This three-way control is called three-way matching on the purchasing side; we discussed the details in the purchase invoice matching control article.
Header-level matching
In header matching, the document is linked to the reference document at the total level. The current account, date, and total amount are compared.
Its advantage is speed. You can approve an invoice with hundreds of lines in seconds. This is sufficient for routine and low-risk purchases.
Its limitation is that if the total matches, details can be overlooked. When one line is overbilled and another is underbilled, the total may still match. Such discrepancies emerge months later as inventory variances.
Therefore, header matching is preferred for speed, not precision.
Line-level matching
In line matching, each invoice line is linked to the corresponding order line. The product, quantity, and unit price are compared individually.
This method shows where the discrepancy is located. Instead of saying "the invoice is 4,200 TL higher," you say "the unit price on the third item is higher than agreed." Negotiations with the supplier are much shorter with this level of clarity.
Line matching also manages partial deliveries correctly. If half of the order arrives, the remaining quantity stays open and matches in the second shipment. We explained the tracking of remaining quantities in the open order tracking article.
Its disadvantage is the time cost. Controlling every line takes time; therefore, matching must be supported by automated suggestions.
Which one should you use and when?
A practical rule of thumb: choose based on risk. Header matching is sufficient for low-value, fixed-price, and regularly recurring purchases.
Use line matching for high-value, variable-price, or multi-item purchases. Raw material purchases, imports, and project-based procurement fall into this category.
A third approach is setting a threshold: invoices above a certain amount are checked line-by-line, while those below are passed at the header level. This is structured together with the approval workflow; you can check out the purchasing approval workflow article.
What to do when discrepancies arise?
Quantity variance. First, check the delivery note. Is it a short delivery or incorrect billing? If there is an acceptance record in the warehouse, the answer is there.
Price variance. If the agreed price and invoice price differ, discuss it with the supplier. The result can be a return invoice, a difference invoice, or acceptance.
Product variance. If there is an item on the invoice that was not ordered, this is either an incorrect document or an unapproved purchase. The latter points to a process issue.
Exchange rate variance. In foreign currency purchases, exchange rate fluctuations between the order and invoice dates create variances. This is an expected situation, not an error; clarify your recording method with your financial advisor.
How a discrepancy is resolved is just as important as who can resolve it. Discrepancies outside the tolerance limit should fall to approval; authorization establishes this distinction.
Definitions that facilitate matching
The difficulty of matching usually lies not in the document, but in definitions. If the supplier issues an invoice with their own product code, automated matching will not work.
The solution is multi-code definition: your code and the supplier's code are matched on the card. We explained this structure in the supplier cards and multi-code article.
Unit discrepancies are also a frequent obstacle. If you work in units and the supplier works in boxes, conversion definitions must be set; you can check out the unit and brand definitions article.
Entering documents with the same screen logic also facilitates matching. Thanks to standard document entry, headers and lines remain in the same place on every document.
Matching on the sales side
Matching is generally associated with the purchasing side; however, the same mechanism operates on the sales side and generates similar value. The difference is that here, control is performed among your own records.
When a delivery note is generated from a sales order, and an invoice from the delivery note, the lines are already linked. Thanks to this connection, the question "how much of this order was shipped, and how much was invoiced" is answered from a single screen; we explained the flow in the sales document chain article.
The most frequent loss when matching is absent is uninvoiced shipments. Goods have gone out, but no invoice has been issued; no one notices at month-end, and revenue is not recorded.
Matching is also required in marketplace sales. When the link between the order coming from the channel and the issued invoice is not established, commission and return reconciliation becomes impossible; you can check out the e-commerce order invoice flow article.
Measuring matching quality
Once matching is established, it is necessary to measure how well it functions. Otherwise, the process may exist on paper but fail in practice.
The simplest indicator is the unreferenced document ratio. The share of invoices processed without being linked to an order indicates how closely the process is followed. If this ratio is high, either the process is cumbersome or the team is bypassing it.
The second indicator is the ratio of documents closed with discrepancies. If discrepancies constantly arise, the problem is not in matching, but in supplier relations or definitions.
The third is the time spent on matching. If the number of minutes per transaction is high, the automated suggestion mechanism is not working sufficiently; multi-code and unit definitions should be reviewed.
When these indicators are read alongside purchasing reports, process improvements are based on concrete data.
Frequently asked questions
Can an invoice arriving without an order be matched?
If there is no reference document, matching cannot be performed; the document is processed directly. The frequency of this situation is an indicator of a process issue.
Can an invoice match multiple orders?
Yes. A supplier can combine several orders into a single invoice; line matching manages this situation correctly.
Does matching make inventory entry automatic?
Yes, when proceeding via the goods receipt record. The inventory module links movements to vouchers.
Where should I track incoming documents?
We covered the daily routine in the incoming e-invoice inbox management article.
Matching is a control that looks like an accounting task but actually measures purchasing discipline. When set up correctly, it prevents overpayments; when not, it silently generates costs.
By meeting with the EQLEM team, you can plan your document matching setup alongside purchasing and inventory.