Opening the business and living with its duties: AA9/12, Comunicazione Unica and yearly obligations

Sara, a psychologist in Florence, starts practising on 2 March 2026 and collects her first fee, 900 €, on 10 March. Her brother Luca opens a small building firm the same day, and a friend of theirs sets up a consulting SRL. Three openings in one week, three different routes to a VAT number, and three calendars of duties that look nothing alike.

Two ways in

The Agency provides two routes to a VAT number, and what separates them is not the tax regime but registration in the business register, the Registro delle imprese. Anyone not required to register uses an Agency form. Anyone required to register goes through the Comunicazione Unica, even when the VAT number is the only formality involved.

For individuals the form is AA9/12. It serves anyone starting a profession, or another activity for which registration in the business register or in the REA, the register of economic and administrative information, is not compulsory. Companies and other non-individuals use form AA7/10.

Anyone opening a business or a craft activity uses instead the Comunicazione Unica d'impresa, an Infocamere service that, in one filing, opens, changes or closes the VAT number and registers the business in the business register or the REA. That is Luca's route, not Sara's.

The AA7/10 page adds a detail for companies: since 1 April 2010 anyone required to register in the business register must use the Comunicazione Unica. It is made up of a cover sheet and the various authorities' forms, lets the filer complete form AA7/10 within it, and is sent electronically to the business register.

The professional: form AA9/12 within 30 days

Form AA9/12 must reach the Agency within 30 days of the date the activity starts. The clock runs from the start, not from the first payment received or the first invoice: for Sara, who begins on 2 March, the first fee on 10 March changes nothing.

The form can be prepared with the Agency's free software, on your own or through an authorised intermediary, and sent straight from the web service in your reserved area. The page also lists three other channels, set out below, with one rule shared by certified email and registered post: the return counts as filed on the day it is sent.

• Certified email (PEC) to any Provincial Directorate, subject "Dichiarazione di inizio attività"; digital signature, or handwritten signature with a copy of an identity document
• In person, or through a delegate, at any Agency office, after booking an appointment
• Registered post to any office, with a copy of the filer's valid identity document
• Web service in the reserved area, after completing the form with the Agency's software

When filing by certified email, the reply comes the same way: the VAT number is sent to the address used for filing. The same form is then used for any change to the details declared and for closing down, again within 30 days, with the subject "Variazione attività" or "Cessazione attività".

Businesses and SRLs: the Comunicazione Unica

The Agency's page on setting up a company recalls that registration in the business register, kept by the Chambers of Commerce, is compulsory for anyone producing goods or services, trading goods, carrying goods or people, doing banking or insurance, or providing services ancillary to those.

Through the Comunicazione Unica a business obtains in one go its VAT number and tax code and opens its insurance and social security positions. Sending it requires three things: joining the free Telemaco service, a digital signature, and a certified email address.

For an SRL the Comunicazione Unica comes after the company's deed of incorporation, which this course does not cover: its content and costs have not been read on a served source, and no figure for them is given here. Choosing an SRL does, in any case, add a step that a sole trader does not have.

The same procedure closes the cycle. When the business ends, the company is removed from the business register after dissolution and any winding-up, through a Comunicazione Unica filing to which the forms for the Agency, INPS and INAIL are added when the change concerns them.

Choosing the flat-rate regime at the start

Someone opening a VAT number has no previous year on which to measure the flat-rate conditions. The regime's page lets them in anyway: in the start-of-business VAT return they state that they expect the conditions to be met. It is a choice to make with the year's numbers in hand.

Before filling in the form it is therefore worth checking the conditions with the dedicated calculator, estimating the year's takings, spending on collaborators and the previous year's employment income. A wrong expectation has consequences: the regime ends once the conditions are no longer met.

The same reasoning works in reverse. A professional who expects takings above the threshold from the first year, or who will work mainly for a former employer, has no grounds to make that statement: they start directly under the ordinary regime, with the duties described further on.

What the flat-rate regime involves each year

On VAT the page on simplifications is clear: a flat-rate taxpayer charges no VAT to customers and deducts none on purchases, does not settle or pay VAT periodically, files no annual VAT return, and does not record invoices issued, takings or purchases.

Some duties remain, however: numbering and keeping purchase invoices and customs documents, certifying takings, and completing invoices for transactions where the taxpayer owes the VAT, paying that VAT by the 16th of the second month after the quarter.

On electronic invoicing the same page contains two sentences that do not fit together: one rules out the obligation, the other lists issuing and receiving electronic invoices among the duties that remain. The page devoted to flat-rate taxpayers explains how to issue one. This course does not resolve the contradiction: check it with your intermediary.

On income tax a flat-rate taxpayer keeps no accounts for tax purposes, is excluded from the synthetic reliability indices, withholds no tax except on employees, and suffers no withholding on fees. On invoices subject to stamp duty they add the 2 € stamp.

What the ordinary regime involves

The ordinary regime is easiest to describe by contrast. Whatever the page spares the flat-rate taxpayer is exactly what stays with everyone else: charging and deducting VAT, settling and paying it periodically, filing the annual VAT return, recording invoices and purchases, keeping accounts.

A professional under the ordinary regime also suffers the advance withholding on fees paid by clients who are withholding agents, and recovers it in their own return. If they in turn pay professionals or employees, they become a withholding agent themselves: a dedicated course describes the single certificate and the calendar that follow.

In return the ordinary regime taxes actual income, real costs included, and has no turnover threshold to respect. For an activity set to grow beyond the flat-rate limits, it is the route that remains open once those limits are passed.

What the SRL involves

An SRL files form Redditi SC every year. According to the Agency's page the return is due by the end of the tenth month after the financial year closes; when the financial year is the calendar year, the date is 31 October. The IRES due is paid on form F24.

The return is prepared with the free RedditiOnLine SC software and sent through the Agency's online services, logging in with SPID, the electronic identity card, the national services card or Fisconline and Entratel credentials. The system first acknowledges the file, then confirms that the return has been filed.

For VAT, bookkeeping and withholding, an SRL follows the ordinary rules: companies have no simplified scheme comparable to the flat-rate regime. That is the administrative price of the company form, to be weighed alongside the difference in rates seen in the first module.

Changing course

No choice is final. A flat-rate taxpayer whose takings pass 100,000 € leaves the regime that same year and charges VAT from the transaction that crosses the threshold; one who loses another condition leaves the following year. Either way the calendar of duties changes overnight.

Someone moving from a sole trader business to an SRL in the same trade must remember the exclusion seen in the first module: controlling an SRL whose activities can be traced back to the individual one rules out the flat-rate regime. The sole trader's VAT number, being a business, is closed through the Comunicazione Unica d'impresa, not form AA9/12.

Leaving the flat-rate regime means taking back, from the year of exit, the duties it spared you: charging VAT, settling and paying it periodically, filing the annual return, recording invoices and keeping accounts. The course on computing and paying VAT describes that calendar, which should be organised before it is needed.

For every switch, keep a simple reminder: the date of the event that triggers it, the form to file and its deadline, and the first duties under the new regime. Anyone passing 100,000 € in October, for instance, must charge VAT from the invoice that crosses the threshold, not from the following January.

One last item comes with every choice: social security contributions. They exist for flat-rate taxpayers, for the ordinary regime and for an SRL's shareholder, and the flat-rate taxpayer deducts them from income. Their amounts are published by INPS in PDF circulars that this course has not read, so no figure for them is given.