A €2,000 gap with what your clients declared brings a letter

Every Italian business that pays a professional’s invoice files a Certificazione Unica the following spring, stating what it paid and what it withheld. The Agenzia delle Entrate adds those certificates up per recipient. If the fees that recipient declared come to at least €2,000 less than the certificates say, they are selected to receive a letter.2

That is rule 10 of twenty-five, set out in the annex to the provvedimento of 14 July 2026 that governs this year’s compliance campaign, covering tax year 2024.1 It is also the most forgiving rule in the document. Twenty of the twenty-five state no tolerance at all.

What the letter actually is

The power comes from three commi of the 2015 stability law. Comma 634 lets the Agenzia put at a taxpayer’s disposal gli elementi e le informazioni in suo possesso riferibili allo stesso contribuente, acquisiti direttamente o pervenuti da terzi — the material it holds about you, obtained directly or arriving from third parties. Comma 636 then requires a provvedimento to name le fonti informative, the sources those elements come from.3 The annex published each July is that list of sources, which is why it can be read as a description of what the state compares.

The subject is the indici sintetici di affidabilità fiscale, the ISA: a reliability score from 1 to 10, established for those carrying on a business, art or profession and computed each year from a long questionnaire attached to the return. The same article switches the ISA off for a year in which the taxpayer started, ceased or was not trading normally, or declared revenue above the ceiling the approving decree sets.4 The letters are not about the score. They are about the data that went into it, and — as five of the rules below show — about who switched it off.

A letter is not an assessment and it does not arrive by post. It is published in the taxpayer’s cassetto fiscale — the online file the Agenzia keeps on each taxpayer — under Consultazioni · ISA/studi di settore · Comunicazioni di anomalia. What arrives is a notification, from complianceISA1@pec.agenziaentrate.it or its sibling address, and the provvedimento is explicit that the anomalies themselves are not in it: le anomalie oggetto di comunicazione non sono esplicitate nei messaggi. Those mailboxes do not accept replies. Anything the taxpayer wants to say back goes through one free application, and errors are put right through the ordinary voluntary-correction route, with the penalty falling the sooner it is done.1

Two lines in the annex’s preamble say more about the exercise than anything else in it. However many anomalies the selection turns up for one taxpayer, the letter carries at most three — le tre diverse tipologie di anomalie più a rischio, the three riskiest found. And the selection is filtered for what the annex calls taluni scarti, discards, of which the example it gives is people who have died since the list was drawn up.2

What gets you picked

Each of the twenty-five rules opens with the population it applies to, and the annex uses four: le imprese, businesses, in eight of them; gli esercenti attività professionale, professionals, in three; i lavoratori autonomi, the self-employed, in one; and i soggetti, anyone at all, in the remaining thirteen.

Five of the rules fire only inside one trade, because each names the ISA questionnaires it applies to — eight distinct ones between them: road haulage, financial advice, commercial agency, and five named by the two construction rules. A haulier who files the haulage questionnaire with no sub-contracting costs, no vehicles and no capital goods is selected on that combination alone — the annex reads it as a form filled in without being answered.

Five more are about having said the ISA did not apply to you. Declaring a period of abnormal trading three years running, claiming the start-of-activity exclusion for a VAT number opened in an earlier year, claiming it twice in three years, claiming cessation twice, or claiming to be over the €5,164,569 revenue ceiling while declaring less than it: each is its own rule. Three further rules do the same for third-sector bodies whose exclusion depended on a State-aid clearance that has not come through.

The six that reach outside the taxpayer’s own paperwork are the ones worth knowing by name. They do not read what you filed against what else you filed; they read it against an archive somebody else filed.

Rule 10 is the €2,000 one, and it is worth reading closely because it is stricter than it sounds. The comparison is not against the fees you declared: it is against the higher of two figures you gave, your professional fees and your VAT turnover. Whichever of those is larger has to come within €2,000 of what your clients certified. Rule 11 does the same arithmetic on people rather than money — declare fewer engagements than the number of clients who filed a certificate for you, by one, and the rule fires.

Rule 8 carries the only exception in the annex that is about living abroad: someone whose ISA model claims employee status without a matching certificate is selected, unless they are registered with AIRE, the register of Italians resident overseas.

Where the margins are

Reading the annex for tolerances rather than for triggers changes what it looks like. Three distinct amounts appear across the whole document, in five of the twenty-five rules.

So the €2,000 is the widest margin the document gives anyone, not the narrowest. In the other twenty rules a single engagement, a single tick in the wrong box or a single year declared the wrong way is the whole test. That is the answer to the question a letter prompts — how far off did I have to be? — and for most of these rules the answer is that being off at all was enough.

None of the five amounts moved this year. Each one appears in the 2025 annex, attached to the same rule, at the same figure.5

Two things about the counting change those numbers, so both are worth stating. Reading the annex as flat text puts its footnotes in the middle of the rules — a footnote sits at the bottom of a page, the rules run across page breaks, and a threshold defined in a note ends up attributed to whichever rule the break happened to land in. Splitting body text from notes by type size fixes that, and the notes were then searched separately for anything the split had thrown away. That search found nothing on its first run, which was wrong: it looked for the phrasing the rules use, and the notes use a different one. Widened, it returns a single threshold — the rents on the lease register have to exceed the declared other income by at least 15% as well as by €5,000 — and that belongs to a rule which already states a euro figure, so the count of rules with no tolerance holds either way.

What changed this year

The 2025 annex had twenty-four rules and this one has twenty-five. Aligning the two editions by rule number, twenty-two of the pairs carry word-for-word the same heading, two gained a condition, and one has no counterpart.

The two that gained a condition are the depreciation rules, one for businesses and one for the self-employed. Last year an anomalous depreciation indicator across three years was enough on its own; this year the taxpayer must also have left the value of their capital goods blank. A condition added to a rule can only narrow it: everyone the 2026 version selects would have been selected by the 2025 one as well.

The rule with no counterpart is number 25, and it is the reason this year’s annex is worth reading even if you read last year’s. It compares the number of engagements a professional declared with the number of distinct clients on the electronic invoices they issued through the state exchange system. Five document types count — invoices, fee notes, simplified invoices and the two kinds of advance — a client is dropped from the tally if a credit note was also issued to them, and clients invoiced only between 1 November and 31 December are not counted at all.2

Rule 11 already did the same arithmetic against the Certificazione Unica in last year’s annex, and the difference between the two is the point. A certificate exists only where the client was an Italian business obliged to withhold tax and file one. An electronic invoice exists wherever one was issued. Adding rule 25 extends the client count from the clients who filed paperwork about you to the clients you billed.

What this does not settle

This is a reading of one document. The annex says who can be selected; it does not say how many letters go out, how many taxpayers each rule reaches, or how many of them turn out on inspection to have done nothing wrong. The Agenzia does not publish those figures alongside the provvedimento, so nothing here supports a claim about how likely any of this is.

Selection is also not a finding. Every rule here is a mismatch between two records, and records mismatch for innocent reasons: a certificate filed for fees that belong to a different year, an engagement split across two invoices, a client who paid late. That is what the reply application is for, and it is why the letter is drafted as an invitation rather than a demand.

Two editions is a short series. The 2025 and 2026 annexes were compared because both are published and machine-readable; a rule that existed in 2023, disappeared, and has now come back would read here as new. And the alignment between them rests on the numbering staying stable, so the word overlap of all twenty-five pairs is published below rather than asserted — anyone who thinks two rules were matched wrongly can see which.