Extensions, instalments and the F24: building a calendar that never misses a payment

Luca, an engineer subject to the ISA indices, declares €3,200 of tax for 2025 and has a €900 balance to pay. On 30 June 2026 he is ready to pay, but his accountant tells him to wait: his deadline is 20 July, with no surcharge. An extension only helps those who know they qualify, and only for the year it was granted.

The 2026 extension for ISA and flat-rate taxpayers

The calendar in the first module applies unless an extension is granted, and every year an extension covers a large share of VAT numbers. For 2026, the Agency's page on income taxes cites Article 6 of Decree-Law 89/2026: taxpayers under the ISA indices, within certain revenue limits, get more time for the June payments.

The scope is precise. It covers anyone running an activity with an approved ISA index, applied or excluded on a recognised ground, whose declared revenue or fees stay within the limit set by the decree approving that index. The limit varies by index and is not quoted in this course.

Flat-rate taxpayers and those in the older 'advantage' scheme are expressly included, as are members of partnerships, associations and businesses meeting the same requirements, whose income is attributed to them on a look-through basis. For a flat-rate taxpayer, then, the extension is the rule rather than an exception to be checked.

It concerns payments due by 30 June 2026 arising from income tax, IRAP and VAT returns. They can be made by 20 July 2026 with no surcharge, or by the thirtieth day after that with 0.80% added as interest.

The extension moves the date, not the substance. Amounts stay the same, and the second advance instalment still falls on 30 November. Anyone outside the scope keeps the 30 June rule, with the option of the following thirty days at 0.40% seen in the first module.

The practical point is that the extension changes every year, by decree. Last year's calendar cannot simply be copied. Early each spring, reread the Agency's income tax page, which gives the dates in force and the legal reference, and update your own calendar accordingly.

Two equal instalments for ISA and flat-rate taxpayers

The first module mentioned that the advance is not split the same way for everyone. For ISA taxpayers, the Agency's income tax page states that each of the two instalments equals 50% of the advance due. The IRPEF page extends equal instalments to flat-rate taxpayers, with the same deadlines as everyone else.

The threshold below which everything is paid in November changes as well. For ISA and flat-rate taxpayers, when the total advance does not exceed €206, it is all paid in November, in one go, by the 30th. Above that figure it is paid in two equal instalments, the first with the balance and the second in November.

Paying the balance and first advance in instalments

Besides deferral there is payment by instalments. The balance and the first advance instalment arising from the income tax return can be paid in monthly instalments. The November advance, however, must be paid in one go: instalments do not apply to it.

The instalment plan must be completed by 16 December. Up to the tax year running at 31 December 2022, payment had to be completed in November: anyone remembering the old rule risks setting up a shorter plan than needed, or thinking fewer instalments are available than there really are.

Interest is due on the instalments, calculated as set out in the return's instructions. This course does not quantify it, because the pages read do not give the rate. Anyone paying in instalments should get the exact amount of each one from whoever prepares the F24, or derive it from the official instructions.

Instalments are a cash-flow choice, not a duty, and they have a drawback: they multiply deadlines. A plan starting in July and ending in December adds five or six dates to the calendar, on top of periodic VAT and the November advance. Without a written calendar, instalments are the quickest way to miss a payment.

Tying the VAT balance to the income tax deadline

Anyone preferring a single summer payment can move the annual VAT balance to the income tax deadline. The Agency's page allows it with a surcharge of 0.40% for each month or part of a month after 16 March. After the move, the balance can still be paid in instalments, adding 0.33% per month to those after the first.

Counting the months is the tricky part: each part of a month counts as a full one. From 16 March to 30 June there are three full months, up to 16 June, plus a fraction of fourteen days. That makes four periods to surcharge, and a total surcharge of 1.60%.

Is it worth it? That depends on what money costs the payer. Sixteen euros per thousand for three and a half months is not negligible, but it can make sense when March cash is tight. The VAT balance instalment calculator lets you compare the four routes on the same amount before choosing.

The F24: channels and rules that always apply

Every payment in the calendar goes through the F24, and for VAT-registered people electronically only. Directly, that means the Agency's two online F24 services, accessed with Fisconline or Entratel credentials, or the internet banking of approved intermediaries. Indirectly, it means an authorised professional or trade association.

Anyone paying a positive-balance F24 through the Agency's services needs an account with an approved bank or with Poste Italiane from which the amount is debited. That is a detail to check before the first deadline, not on the day itself.

Two rules apply whether or not you hold a VAT number. Offsetting VAT credits, income tax and surtax credits, substitute tax credits, IRAP credits or the credits reported in section RU requires the Agency's online services. The same goes for a zero-balance F24, where credits cover the debts entirely.

Receipts matter as much as payments. Every electronic F24 generates a receipt, and filing receipts by year and by item lets you reconstruct in minutes what was paid and when. It is also the first thing to check if a notice of irregularity arrives.

The shortest calendars: flat-rate taxpayers and the 730

A flat-rate taxpayer's calendar is far lighter than an ordinary professional's. The scheme exempts them from settling and paying VAT and from the annual VAT return, so the 16th-of-the-month deadlines and the March balance do not concern them. Income taxes remain, with the summer extension and the second advance in November.

One exception is easy to forget. When a flat-rate taxpayer is liable for the tax on a purchase, for instance under reverse charge, they complete the invoice with rate and VAT and pay that VAT by the 16th of the second month after each calendar quarter. Anyone making such purchases adds four dates to their calendar.

People without a VAT number who file the 730 return live by yet another calendar. With a withholding agent, an employer or pension body, the adjustment is made directly on salary or pension from July, and no F24 has to be filled in personally.

Those filing the 730 without a withholding agent, or the Redditi return without a VAT number, pay by F24 on the same dates as everyone else. Not holding a VAT number, they may also use the paper form at a bank, a post office or a collection agency counter, unless they offset credits or submit a zero-balance F24.

Several of these calendars often coexist in one household: an employee spouse filing the 730, a self-employed partner with a VAT number, perhaps a child under the flat-rate scheme. Keeping every date in a single family calendar, with the payer's name next to each item, avoids mixing up one person's rules with another's.

Building your own calendar

The calendar is built once, in January, and updated in spring. The starting point is your own position: ordinary or flat-rate regime, monthly or quarterly VAT, subject to ISA or not. Those three answers determine almost every date of the year.

• Write down every date of the year with the item and tax code, starting from your own position
• Flag deadlines falling on a Saturday, Sunday or holiday and bring them forward to the previous working day
• Reread the Agency's pages in spring for that year's extensions
• Estimate the June and November amounts with the advance calculators, before May
• Set aside a share of each month's receipts in a separate account
• File F24 receipts by year and by item

Setting money aside is the part no official page requires, yet it decides whether the calendar is kept. Anyone putting away a share of receipts every month reaches June with the money ready. Anyone who does not finds out at the end of June that the only choices left are deferral, instalments or paying late.

The tool matters little: a spreadsheet, a phone calendar, the accountant's software. What matters is that the dates are written in one place, with a reminder a few days ahead. A few days' margin protects against weekends, internet banking glitches and plain forgetfulness.

A good calendar is also reviewed at year end. Which deadlines were met comfortably, which on the last day, which were missed? The answers show where to move a reminder, where to raise the set-aside, and whether switching between quarterly and monthly VAT settlement makes sense, when the conditions allow it.

If a deadline is missed despite everything, the calendar does not end there. Voluntary correction, the ravvedimento operoso, lets taxpayers regularise a late payment themselves with reduced penalties and interest, which are lighter the sooner they act. It is a remedy, not a strategy: its cost grows with each day of delay.