Inarcassa contributions — engineers & architects 2026

How much does an engineer or architect pay to Inarcassa? Soggettivo 14.5%, integrativo and 2026 minimums

TaxDemocracy calculates fund contributions and tax (flat-rate scheme or IRPEF) in a single tool, with a projection of the next 5 years.

Annual revenue

€

Your gross annual revenue, before taxes and contributions.Under 35

Enrolled less than 5 years ago

Applies the fund’s break on the minimum contributions.

ATECO code

Determines the flat-rate profitability coefficient.

Municipality of residenceNeeded for the surtaxes, and so the net income.

Enter revenue, ATECO code and municipality.

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An engineer's and architect's Inarcassa contributions: three separate items, and the minimums are due even at zero revenue

If you're an engineer or architect registered with the professional board and holding a VAT number (partita IVA), Inarcassa asks you for three things: the subjective contribution, equal to 14.5% of net professional income up to 145,550 euros; the supplementary contribution, the 4% you charge to clients in your invoices on your turnover; and the maternity and paternity contribution, a fixed amount of 91 euros. Each of the first two has a minimum that's independent of turnover: in 2026 they're 2,785 euros of subjective and 850 of supplementary. Adding it all up, the year starts at 3,726 euros even if you've issued a single invoice.

The point that contribution calculators ignore is that Inarcassa doesn't live on its own: the contributions paid are deducted from income, so they change the tax, which in turn depends on the scheme (flat-rate at 15% or 5%, or IRPEF by brackets). And in the early years the under-35 discount and the minimum waiver come into play, which can more than halve the bill. Below you'll find the 2026 rules with an example on 40,000 euros of turnover; for your exact numbers, the tool puts tax and fund together in one go.

How the calculation works on TaxDemocracy

1
Enter your expected turnover, your tax scheme (flat-rate or standard) and how many years you've been registered with Inarcassa: age and seniority are needed to apply the young-professional reliefs, if you're entitled to them.
2
The tool calculates the subjective, supplementary and maternity contributions with the 2026 minimums, deducts the contributions from income and calculates the substitute tax or IRPEF with surtaxes on top.
3
You see the net you're left with and the projection over the next 5 years, year by year, with balances and advance payments. No registration and no leaving your email.

Inarcassa contributions compared, in two charts

Computed with the 2026 rules, assuming the 78% profitability coefficient for the profession (income = revenue × 78%).

1. What you pay and what you invoice

The soggettivo (14.5%) plus maternity are out of pocket; the integrativo (4%) is invoiced to the client. Both have a floor — €2,785 soggettivo, €850 integrativo — paid even at near-zero revenue: the flat plateau on the left of the chart.

Out of pocket (soggettivo + maternity)Integrativo 4% (in-invoice)

2. Under 35 vs standard member

Members enrolling before 35 pay, for the first 5 years, the soggettivo at 7.25% with the floor cut to a third (€928 instead of €2,785). The gap between the two lines is all on the left: the discount matters exactly when revenue is low.

Standard memberUnder 35

Soggettivo 14.5% (floor €2,785, income cap €145,550), integrativo 4% (floor €850), maternity €91. Under 35: soggettivo 7.25% (floor €928.33) for the first 5 years. Maternity is a flat amount. 2026 figures, estimate.

What you pay to Inarcassa: three revenue scenarios

Contributions on the flat-rate regime (income = revenue × 78%), standard member.

Revenue	Out of pocket	Integrativo	Fund total
€25,000	€2,919	€1,000	€3,919
€40,000	€4,615	€1,600	€6,215
€60,000	€6,877	€2,400	€9,277

Out of pocket = soggettivo + maternity. The integrativo is invoiced to the client. Net income also depends on tax: use the calculator above.

Inarcassa contributions for engineers and architects: soggettivo, integrativo and maternity on €40,000 of revenue

Take an architect in the flat-rate scheme (regime forfettario) who bills 40,000 euros a year, registered for more than 5 years (so without the young-professional reliefs). The profitability coefficient for the profession is 78%, so the income on which the subjective contribution is calculated is 31,200 euros.

Subjective contribution: 14.5% of 31,200 = 4,524 euros. It's above the minimum of 2,785, so you pay the full amount: the minimums in June and September, the balance by 31 December of the following year.
Supplementary contribution: 4% of 40,000 = 1,600 euros. This, however, you charge in your invoices: your clients pay it, you collect it and pass it on to Inarcassa. It's not income and you don't pay tax on it.
Maternity/paternity: 91 euros fixed, the same for everyone.

So around 4,615 euros comes out of your own pocket (subjective plus maternity); the supplementary passes through your account but the cost falls on the client. The minimums are paid in two equal instalments, 30 June and 30 September, or in six bimonthly instalments. Above 145,550 euros of income the subjective contribution stops: it's not due on the excess.

The full calculation includes the tax: on the 31,200 euros of flat-rate income, after deducting the 4,615 of contributions paid, 26,585 euros of taxable income remain. At 15% that's around 3,988 euros; with the 5% start-up rate, around 1,329. In total, between fund and tax, on 40,000 euros billed you keep between 31,000 and 34,000 in hand depending on the rate.

Engineer or architect under 35: minimums, waiver and the early-years discount

The minimums are the real obstacle of the early years: 3,726 euros in 2026 regardless of turnover. There are, however, two ways to ease them.

The first is the waiver of the minimum subjective contribution: if you expect professional income below 19,207 euros, you can ask Inarcassa (the application is filed online by the end of May) not to pay the minimum of 2,785 euros and instead pay 14.5% of your actual income alone, settled the following year. With 8,000 euros of income you'd pay 1,160 euros instead of 2,785. The supplementary minimum of 850 euros and the 91 of maternity remain due. Note: a waiver year counts for less towards your pension, in proportion to what you paid, unless you top it up later.

The second is the young-professional relief: anyone who registers before the age of 35 pays, for the first 5 years, the subjective contribution at a halved rate of 7.25% and the minimums reduced to a third: 928.33 euros of subjective and 283.33 of supplementary in 2026. The first year for an under-35 therefore starts at around 1,303 euros, not 3,726. The 4% rate in invoices, by contrast, stays at full. The reduction only applies if income doesn't exceed the members' average (around 46,300 euros); anyone who stays registered and pays for at least 25 years recovers the discounted years with a notional contribution, so the discount isn't necessarily paid for with a leaner pension.

Engineer or architect on the flat-rate regime with Inarcassa: compatible, but no 35% reduction

There's a common misunderstanding about the flat-rate scheme: the 35% contribution reduction that many guides talk about applies only to artisans and traders registered with INPS. Anyone registered with Inarcassa has nothing to do with that measure: the fund contributions are paid in full, flat-rate scheme or not. The scheme remains worthwhile for many engineers and architects, thanks to the 15% rate (5% for the first 5 years of a new activity) and the bare-bones bookkeeping.

Two details that make the difference in your return. First: the 4% supplementary contribution charged in your invoices counts neither towards income nor towards the 85,000-euro limit of the flat-rate scheme, unlike the 4% INPS surcharge of professionals without a fund, which is instead a fee in every respect. On 40,000 euros of turnover you can therefore collect 41,600 without eating into the cap. Second: the compulsory contributions paid during the year (subjective, maternity and any remaining supplementary minimums left on your side) are deducted from the flat-rate income in the LM section, before calculating the substitute tax. It's a deduction many forget and which, on 4,600 euros of contributions, is worth almost 700 euros less in tax at 15%.

The interplay between the 78% coefficient, the deduction of contributions and the reduced rate makes the manual calculation slippery. The tool does the steps in the right order and also shows you what happens when the rate moves from 5% to 15%.

Frequently asked questions

How much does an engineer or architect pay to Inarcassa in the first year with a VAT number?

It depends on your age. If you register before turning 35, the 2026 minimums reduced to a third come to around 1,303 euros (928.33 of subjective, 283.33 of supplementary, 91 of maternity), plus any balance at 7.25% if income exceeds the minimum. After 35 you start from the full minimums, 3,726 euros. In both cases, if you register part-way through the year the minimums are pro-rated to the months actually registered, so opening in September costs about a third of opening in January.

Does an engineer or architect have to pay the Inarcassa minimums even with no revenue?

In principle yes: the minimums are independent of turnover. But for the subjective contribution there's the waiver: if you expect income below 19,207 euros (2026 threshold), you file an application online by the end of May and pay only 14.5% of actual income as a balance. With zero income, zero subjective. The supplementary minimum of 850 euros and the 91 of maternity remain due. A waiver year, however, counts for less towards your pension, in proportion to what you paid.

The 4% Inarcassa integrativo: does the professional pay it, or the client?

The client pays it: you charge it in your invoice as a separate item on the taxable amount, collect it and pass it on to Inarcassa. For you it's not income, you don't pay tax on it, and under the flat-rate scheme it doesn't eat into the 85,000-euro limit. The flip side is the minimum: if 4% of your turnover doesn't reach 850 euros (that is if you bill less than 21,250 euros), the difference up to the minimum stays on your side.

Can an engineer or architect use the flat-rate regime with Inarcassa?

Yes, and for many engineers and architects it's the most worthwhile combination: a profitability coefficient of 78%, tax at 15% (or 5% for the first 5 years) and the contributions paid deductible from flat-rate income. The only caveat is not to expect the 35% contribution reduction: it's a measure reserved for INPS artisans and traders and doesn't apply to professional funds. To see the combined effect on your turnover you can simulate tax and Inarcassa in a couple of minutes, free.

Are engineers and architects’ Inarcassa contributions tax-deductible?

The subjective contribution (including the voluntary one) and the maternity contribution are fully deductible: under the standard scheme from total income pursuant to art. 10 of the TUIR, under the flat-rate scheme directly from taxable income in the LM section, before the substitute tax. The supplementary one charged in your invoices, by contrast, is not, because the cost falls on the client, not on you. On 4,600 euros of deducted contributions, at a 15% substitute tax the saving is worth almost 700 euros.

Sources: Inarcassa regulation, 2026 rates and minimums (inarcassa.it). Estimate, not a substitute for professional advice.