Belgian commercial practice attaches a strong consequence to silence: a business that receives an invoice and does not protest it within a reasonable time is presumed to have accepted it. For you as a creditor, that presumption is one of the most useful things in the file.
But two different questions hang on the same word "disputed", and they have different answers. The first is practical: can you still use the fast administrative route? The second is legal: does the protest actually stand up? Get these two apart and the rest of this article — and most of your collection strategy — follows.
For the administrative route, every objection counts as a dispute
The IOS procedure is open only for undisputed claims, and Belgian practice reads that strictly. A protest that arrives far too late, one that is manifestly unfounded, or one that says nothing more than "we contest this invoice" without a single reason — each of them takes the administrative route off the table. The bailiff cannot weigh whether the objection is any good; that assessment belongs to a judge.
This is worth knowing before you are surprised by it. A debtor who has learned the trick can close off the cheap route with two lines of e-mail. What that debtor cannot do is make the debt go away: a worthless protest costs you the shortcut, not the claim. It moves the file to court, where the objection is examined on its merits — and where, as our article on the two routes shows, you can in fact claim considerably more.
Whether the objection holds up is a separate question
Before a judge, the objection is measured against four requirements. They decide whether your debtor still benefits from the presumption of acceptance or has to make their case.
In time
"As soon as circumstances allow" is the standard, and circumstances differ. Goods that were never ordered call for an immediate reaction. A complex service may reasonably need time to inspect. What does not pass is a protest that surfaces for the first time when the bailiff knocks, months later.
Motivated
"We dispute this invoice" is not an argument. The reasons why the invoice is wrong have to be described clearly: what was not delivered, what was defective, which price was agreed instead. Before a judge, a bare denial carries very little weight. Note the asymmetry, though, and it is the point of this article: that same bare denial is still enough to close the administrative route.
In writing
A phone call has no evidentiary value; six months later there are two versions of it and no record. Registered mail remains the safest route. That said, where the parties habitually deal with each other by e-mail, ordinary e-mails sent from and to the known addresses are generally accepted as proof — which cuts both ways: your debtor's protest by e-mail counts, and so does your own correspondence.
Against the right terms
The small print on the back of the invoice matters here: a contractual period for complaints, if properly communicated and agreed, sets the deadline. Which is why a creditor should have such a clause and a debtor should read it.
Two practical points
"I never received the invoice." If your debtor did not receive the invoice but did receive the reminder, the obligation to react starts running from the moment they learn of it. Silence after a reminder is still silence.
Partial disputes. A debtor who genuinely disagrees with part of an invoice should set out the reasons in writing and pay the undisputed remainder. Someone who withholds the whole amount over a contested fraction is in default for the rest — and that is a position we can act on immediately.
When you upload an invoice with us, you confirm it was never disputed. Take that literally: any written objection from your debtor counts, even a late one, even a groundless one, even a bare "we contest this". Tell us if one exists — it does not stop us, it changes the route we take, and knowing it at the start saves a wasted step.