How the number is arrived at
Interest runs from the day payment became due, not the day you sent the invoice, and it accrues day by
day until the money lands. The formula is the same shape in every regime here: a reference rate set by a
central bank or by the authority acting on it, plus a margin the law guarantees you, applied to the
outstanding amount for the number of days late.
European Union
Directive 2011/7/EU on combating late payment in commercial transactions gives a creditor in a
business-to-business or business-to-public-authority debt the right to interest at the European Central
Bank's main refinancing operations rate plus a minimum of 8 percentage points, from the day after the
payment date. Article 2(8) fixes the base rate once per half-year: it is the rate applicable to the most
recent main refinancing operation adopted before the first calendar day of that half-year. That is why the
number in the box can differ from the ECB rate you see quoted in the news today, and it is editable for
exactly that reason. Article 6 adds the right to recover reasonable collection costs and at least
€40 per invoice.
Member states implement this as a floor, not a ceiling. Several set a higher margin or a larger fixed
recovery sum in their own national law, and public authorities in some states pay a higher rate than
private clients do. If your client is in a specific country, check that country's implementing rules
against this minimum before you quote a figure. Finland is a good example of why: it does not use the ECB
rate at all, so the EU row above would give you the wrong Finnish number.
Finland
Korkolaki (Interest Act) 633/1982 sets the rate from a reference figure called the viitekorko,
which Suomen Pankki publishes twice a year, for the periods starting 1 January and 1 July. It is not the
ECB rate: the law takes the ECB main refinancing rate in force before the first day of the period and
rounds it up to the next whole half percentage point. For 1 July–31 December 2026 the published
viitekorko is 2,5 %, from which:
- 10,5 % a year — reference rate plus 8 points, where the debt is between businesses or owed
by a public authority (4 a§, the "kaupallinen sopimus" case). This is the ordinary freelancer-to-client
invoice.
- 9,5 % a year — reference rate plus 7 points, for any other late debt (4§), including
one owed by a private individual.
Interest runs from the day after the eräpäivä, the due date. On top of it you can claim the fixed
recovery compensation of €40 per invoice, which is the sum the EU directive required member
states to make recoverable; it applies to business and public-authority debts, and further reasonable
collection costs can be claimed insofar as they exceed it. If your own agreement sets a different
late-payment rate, that term usually governs instead of the statutory figure, and Finland has specific
rules about contract terms on interest that a court can adjust — a clause that is grossly unfair to a
small business is not automatically enforceable. Choose the "My own contract rate" row for that case.
One thing this tool cannot tell you: whether your claim is business-to-business. The difference
between 10,5 % and 9,5 % is decided by who owes the money, not by how late it is, so if the client is a
private person or an individual trader billing you as a consumer, use 7 points in the margin box.
Samat luvut suomeksi: FreelanceDesk suomeksi —
sivu suomalaiselle yrittäjälle, jossa ALV-kannat, laskun pakolliset tiedot ja korkolain korot on koottu
yhteen. Tämäkin laskuri toimii omassa selaimessa ilman internetiä, eikä se lähetä syöttämiäsi tietoja.
United Kingdom
The Late Payment of Commercial Debts (Interest) Act 1998 implies a right to interest into commercial
contracts where the contract is silent, at the "standard rate": 8 percentage points above the Bank of
England base rate. Two details that catch people out. The Act fixes the relevant rate by reference to
the day the payment became due, so if the base rate has moved since then you should use the rate for that
date rather than today's. And the Act also gives a fixed sum instead of, or alongside, recovery costs:
£40 for a debt under £1,000, £70 from £1,000 to £20,000, and
£100 above £20,000, plus reasonable costs of using a debt-collection agency.
What this tool will not do for you
- It is not legal advice and not a court-ready pleading. It is arithmetic on a rate you confirm.
A tribunal or court will want the rate, the period and the basis stated, so keep the inputs you used.
- It assumes a commercial debt. These statutes do not generally reach an individual who owes you
money personally. Use the contract option for that, with the rate your own terms set.
- It cannot know what your contract says. An express late-payment clause usually wins, and it can
be more generous than the statutory floor. Where a contract term is grossly unfair to a small business,
the statutory right can still apply — that is a question for the rules of your jurisdiction.
- It does not convert currencies. If you invoice in naira or dollars and claim the €40 or
£70, the tool shows that statutory amount in its own currency and leaves the exchange to you,
because an invented rate inside a money claim is worse than none.
- It does not model VAT on the interest. Late-payment interest and compensation can have their own
tax treatment. Ask an accountant before you add a line to a VAT return.
A worked example, line by line
Three sums: one in euros under the EU directive, the same invoice again under Finnish national law, and
one in pounds under the UK Act, using the reference rates in force for the dates below. Rounding is to the
cent, which is what the calculator does; a court claim should also state the daily rate, so the figure can
be recalculated to the date of judgment.
€1,200 due 1 August 2026, paid 1 October 2026
- Rate: ECB main refinancing operations rate 2.40% for the second half of 2026, plus the
directive's minimum 8 percentage points = 10.40% a year.
- Days: 61. Interest starts the day after the due date, so it runs from 2 August to
1 October inclusive.
- Interest: €1,200 × 10.40% × 61/365 = €20.86. The daily figure
is €1,200 × 10.40% ÷ 365 = €0.3419, which is the number worth quoting
to the client.
- Recovery costs: at least €40 under Article 6, so the claim is
€60.86.
- If it is paid three weeks later instead (21 more days): 21 × €0.3419 =
€7.18 more interest, a claim of €68.04. That is the number that makes waiting feel
expensive, which is the point of quoting it early and calmly.
€1,200 due 1 August 2026, paid 1 October 2026 — under Finnish law instead
Same invoice, same dates, but the client is in Finland, so the basis is korkolaki rather than the
directive's minimum.
- Rate: Suomen Pankki's viitekorko for 1 Jul–31 Dec 2026 is 2,5 %. Against a business
client the Act adds 8 points = 10,50 % a year, not the 10,40 % the EU row would have given, because
Finland rounds the reference rate up to the next half point first.
- Days: still 61, from 2 August to 1 October inclusive.
- Interest: €1,200 × 10.50% × 61/365 = €21.06, at
€0.3452 a day.
- Recovery compensation: €40, so the claim is €61.06.
- If the debtor is a private individual, the margin is 7 points and the rate 9,50 %: the same 61
days cost €19.05, a claim of €59.05. That is the difference between the two Finnish rows, and no
amount of waiting changes which one applies.
The 20-cent gap against the EU minimum on this invoice is nothing. The basis still matters, because on a
larger debt, or against a private client where the two differ by almost a whole percentage point, the wrong
formula is a wrong claim — and a claim you cannot explain is worse than no claim.
£5,000 due 1 September 2026, paid 28 October 2026
- Rate: Bank of England base rate 3.75% plus 8 percentage points = 11.75%, the Act's
standard rate.
- Days: 57, from 2 September to 28 October inclusive.
- Interest: £5,000 × 11.75% × 57/365 = £91.75, at
£1.6096 a day.
- Fixed sum: £70, because a debt between £1,000 and £20,000 falls in the
middle band. The claim is £161.75.
- Three more weeks: 21 × £1.6096 = £33.80, a claim of
£195.55.
Two details those sums show. The compensation is not interest and does not grow with delay: it is a
fixed contribution towards chasing, so it matters most on small invoices, where £70 can dwarf the
interest. And because the rate is fixed by the due date rather than by today, an invoice that has been
late since before a rate change keeps the old rate — which is why the calculator lets you type the
rate rather than guessing it from the news.
Whether to actually charge it
Most freelancers never send the bill. That is usually the right call on a first late invoice from a good
client: chasing a few euros of interest can cost a relationship worth a year of work. Where it earns its
place is the client who is chronically late, because there the charge is not a punishment, it is the only
thing that makes your payment terms mean something. A common middle path is to put the due date, the
statutory rate and the fixed sum in your terms from day one and only apply them on the second or third
overdue invoice. Having the rate in the contract is what makes quoting it later normal rather than hostile.
Privacy
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server, and the only thing remembered is your last set of inputs, in this browser's local storage on this
device, so the fields are still filled when you come back. Clearing site data for this host removes it.
See the privacy notice.