Three English markets, three sets of law — and why that is a trap we have already fallen into

This guide is about a mistake that is easy to make, hard to see, and which we have made twice.

One language, three jurisdictions

English is one of Malta's own official languages. It is also the language of the United Kingdom and of Ireland, and all three are markets we run.

So there are now three places in our registry where the language is `en` and the law is different:

• Malta — ECB reference rate plus eight points, in euro, and the sources are explicit that the interest is simple.
• Ireland — ECB rate plus eight points, in euro, fixed for six-month periods.
• The United Kingdom — the Late Payment of Commercial Debts (Interest) Act 1998, Bank of England base rate plus eight points, in pounds, with a statutory fixed sum rather than the directive's compensation.

A piece of text picked by language would serve all three from whichever entry it found first.

We did exactly that, twice

This is not a hypothetical risk we are describing in advance. It is a bug we shipped and then found.

The reminder letter cited the Danish Interest Act and a fee of «40,00 kr.» to British and Dutch customers. The registry said those markets were open; the letter said something else entirely. It was the customer's name on the letter, not ours.

The VAT endorsement on invoices was selected by the language of the document rather than the country of the seller, so a Dutch seller's invoice carried a reference to the Danish VAT Act.

Both had the same shape: a text correct for the market it was written for, reused for a market that shares its language.

What we changed

Not the letters. The test.

Every piece of customer-facing legal text is now run against every market, and each run is checked against that market's own jurisdiction — not against the first plausible match. The currency is checked by rendering an actual amount in that market's currency, because a number formatted as kroner looks entirely reasonable until you know it should have been pounds.

The reason to test it that way instead of reading the code is that the code looked right both times. What was wrong was the assumption that a language identifies a country, and an assumption does not appear in a diff.

Adding Malta was the first real test of that: three English markets instead of two. The guards had something to say, which is the whole point of having written them.

What we cannot do here

Two things, and both are gaps rather than refusals.

The fixed recovery compensation we have not read — neither the amount nor the regulation. The calculation refuses it rather than putting a figure nobody has read into a demand with your name on it.

The reference day for the statutory rate we have not read either. Eight points over the ECB reference rate is clear enough; which day's rate is not. Slovenia says the half-year. The Czech Republic locks it to the half-year the default began in. Finland rounds the ECB rate up to the nearest half point first, so Finland and Ireland produce different numbers from the same eight points on the same day. Four countries, four answers to one directive — which is why we do not read Malta's answer off a neighbour. Our calculation asks the caller for the day and refuses without it.

Sources

The statutory rate — ECB reference rate plus eight percentage points, simple interest — and the VAT rates of 18 %, 12 %, 7 % and 5 % were read on 27 September 2026 in professional sources and in references to finance.gov.mt, not in the Act or the regulations themselves. The reference day was not read at all. We say so, so that you know how well we know it.