Why Customers Pay Other Suppliers First (and How to Get Your Invoice Paid First)
When cash is tight, customers don't pay suppliers in date order. Here are the five rules accounts payable actually uses, and how to make them work for you.
You delivered on time. Your invoice is correct. Your reminders are friendly. And somehow, every month, other suppliers get paid before you. It isn't bad luck. When a customer has less cash than bills, somebody in accounts payable decides who gets paid this week, and they don't decide by date order.
This guide goes inside that decision. It covers the rules accounts payable teams actually use, why polite, open-ended reminders sink to the bottom of the pile, and how to move your invoice to the top without becoming unpleasant. The worked examples use Spain's late-payment rules, which are among the clearest in Europe.
First, a short film. It's the first episode of Accounts Payable, set inside a Barcelona hotel group's finance chat on payment-run day: €40,000 available, €190,000 due.
The short answer
To get your invoice paid first:
- Be hard to skip: make sure what you supply is visibly essential, and that someone at the customer knows it.
- Make your invoice pass the match first time: the right legal entity, the purchase order number, and amounts that match the order and the delivery.
- Give paying early a reward: a small early-payment discount moves invoices up fast.
- Give waiting a cost: in most of Europe, including Spain, the law already adds interest and fixed compensation to late invoices. Say so.
- Give every reminder a deadline and a next step: "whenever convenient" is an invitation to wait.
How accounts payable actually decides who gets paid
When cash is tight, finance teams sort their unpaid invoices into a queue. The details vary, but most follow the same five rules, whether or not anyone has written them down.
Rule 1: critical suppliers first. If a missed payment would stop the business (power, payroll, key materials), that supplier gets paid first. One-off or easily replaced suppliers can wait a few extra days.
Rule 2: discounts jump the queue. An early-payment discount is money for the payer. A 2% discount for paying within ten days is worth far more than it looks when you work it out as an annual rate, and finance teams know it.
Rule 3: no match, no payment. Most companies check each invoice against the purchase order and the delivery record, known as the "three-way match". If the price, the quantity, the company name or the PO number doesn't match, the invoice is blocked until someone fixes it. Blocked invoices don't get paid, however long they wait.
Rule 4: quiet and patient goes last. Suppliers who chase politely, with no deadline and no consequence, are the easiest to postpone. Nobody means it unkindly. It's simply the lowest-risk choice.
Rule 5: a deadline, a cost and a next step go first. When waiting starts to cost money, or a clear escalation is on its way, an invoice moves from "later" to "now". That's what happens in the film: the same supplier goes from last to first in one email.
Rule by rule: how to move your invoice up
| AP rule | What it means for you | What you can do |
|---|---|---|
| Critical suppliers first | Replaceable suppliers get squeezed | Make your role visible: lead times, stock you hold for them, the next delivery that depends on payment |
| Discounts jump the queue | A small incentive changes the order | Offer a modest early-payment discount on large invoices, if your margins allow it |
| No match, no payment | One wrong detail blocks the invoice | Get the PO number before you ship, and invoice the exact legal entity on the order |
| Quiet and patient goes last | Friendly reminders are easy to postpone | Keep the tone warm, but add a date and a next step to every reminder |
| Deadline, cost and next step go first | Consequences move invoices | State the legal interest and compensation, and what happens if the deadline passes |
Make your invoice pass the match first time
A surprising share of "late" invoices aren't late because the customer is short of cash. They're stuck, because accounts payable can't match them. Before you send an invoice, check:
- The customer's exact legal name and tax number, as on the purchase order. "Casa Nuvola LLC" and "Casa Nuvola Hotels, S.L." are different companies to an accounts system.
- The purchase order number, and the line numbers if the order has several.
- Quantities and prices that match the order and the delivery note exactly.
- The correct invoice address or accounts-payable email, not the buyer's personal inbox.
- Your bank details, and the due date written in full.
- For customers in Spain, any e-invoicing format or portal they require.
If a customer says the invoice never arrived, our guide to proving delivery and getting paid covers what to do next.
Give waiting a price: late payment rules in Spain
Many suppliers don't realise that the law may already put a price on late payment. In Spain, B2B late payment is governed by Ley 3/2004 on combating late payment in commercial transactions, which implements the EU Late Payment Directive.
- Payment terms: the default term is 30 days. The parties can agree a longer term, but not beyond 60 days.
- Interest applies automatically: when an invoice is paid late, statutory interest is owed without any need for a reminder or formal notice.
- The rate: the European Central Bank's main refinancing rate plus 8 percentage points, published every six months. For the second half of 2026 it is 10.40% a year. It was 10.15% in the first half.
- €40 per invoice: the creditor is entitled to a fixed €40 for collection costs, added automatically. Spain's Supreme Court has confirmed it applies to each late invoice, not once per claim. Documented collection costs above that can also be claimed.
Here is the film's example: three unpaid invoices totalling €31,400, paid 45 days late in the second half of 2026.
| Item | Amount |
|---|---|
| Unpaid invoices (3) | €31,400.00 |
| Statutory interest: €31,400 × 10.40% ÷ 365 × 45 days | €402.60 |
| Fixed compensation: 3 invoices × €40 | €120.00 |
| Total owed | €31,922.60 |
Other EU countries follow the same directive, with the same 8-point margin over the ECB rate and a minimum €40 per invoice, although the details vary. In the UK, the equivalent rules add 8% over the Bank of England rate and up to £100 per invoice; see our guide to late payment interest in the UK.
This is general information, not legal advice. Your contract, the parties and the facts can change the answer.
How to chase without being "lovely and ignorable"
Politeness isn't the problem. Vagueness is. A reminder that moves invoices up the queue stays courteous, but it always contains three things:
- A date: "Please confirm payment by Friday 17 October", not "whenever convenient".
- A cost: "Under Spanish law, late payments carry statutory interest (currently 10.40%) and €40 per invoice", stated as a fact, not a threat.
- A next step: "If payment isn't received by then, we'll pass the file to our collection partner."
Send it to the accounts-payable address and copy your contact at the customer. Then do what you said you'd do. The next step only works once the customer believes it.
When to hand it over
If two clear reminders with a deadline have passed, the invoice is unlikely to rise in the queue on its own. At that point a letter from a collection agency often does what a supplier's own emails couldn't. It adds the interest and compensation the law allows, sets a short deadline, and makes clear that a court payment order (in Spain, the proceso monitorio) is the next step. That's the email that moved Porto from fifth to first in the film.
If you're wondering what a collector costs, here is how much debt collection agencies charge.
Frequently asked questions
Why do customers pay other suppliers before me?
Because accounts payable prioritises by risk and value, not by date. Critical suppliers, invoices with early-payment discounts, and suppliers who attach a deadline and a cost to late payment usually go first. Invoices that don't match the purchase order are blocked, and polite reminders with no deadline are the easiest to postpone.
What is the three-way match?
It's the check most accounts payable teams run before paying: the invoice is compared with the purchase order and the delivery record. If the price, the quantity, the company name or the PO number doesn't match, the invoice is blocked until someone resolves the difference.
What is the late payment interest rate in Spain in 2026?
For B2B transactions under Ley 3/2004, the statutory rate is the ECB's main refinancing rate plus 8 percentage points. It is 10.40% for the second half of 2026 and was 10.15% for the first half. It applies automatically when payment is late, with no reminder needed.
Can I charge €40 per late invoice in Spain?
Yes. Ley 3/2004 gives the creditor a fixed €40 for collection costs when payment is late, added automatically to the debt. Spain's Supreme Court has confirmed that it applies to each late invoice. Documented collection costs above €40 can also be claimed, unless the debtor isn't responsible for the delay.
What is the maximum payment term between businesses in Spain?
The default term is 30 days from delivery of the goods or services. The parties can agree a longer term, but it can't exceed 60 days.
Should I offer an early-payment discount?
It can work well for large invoices, because finance teams prioritise discounts. Keep it modest, set a short window, and make sure your margins can absorb it. A clear deadline and a stated cost for late payment are free alternatives that also move invoices up the queue.
Get to the top of the pile
Linhos do Porto went from last in the queue to first in one email, without raising its voice. INTERCOL recovers B2B debts in Spain and worldwide, adding the interest and compensation the law allows and a deadline your customer believes. We work on a no cure, no pay basis: if we don't recover, you don't pay. Tell us about your unpaid invoice.