Mastro — the operations software for accounting firms: mail, deadlines, F24, signatures, payments

A month with a new client

Rossi Srl comes in on day 1.
Here is its first month.

Nine real moments. Each one says who does what: the firm, the client from their phone, or Mastro on its own.

The firmdoes something
The clientdoes it from their phone
Mastrodoes it on its own

Day 1 · 9.12 am
Rossi Srl arrives. You type the VAT number, nothing else.
Company name, registered office, ATECO code, director: they come from the business registry. From here on that data flows on its own into the engagement, anti-money-laundering, deadlines and invoices.
In detail: who does what
Registry extracts and client records
1. The firm
  You look up the company
  VAT number or tax code. The data comes from the Business Register. You buy the official extract from there and it goes on file.
2. Mastro
  Imports without duplicates
  From a file or from your accounting software's export. Before saving, it shows you what it adds and what it merges.
3. The client
  The client corrects their own details
  From their profile, when their address or phone changes. One record, shared by every module.
01234567897
Mastrofound in the Business Register
Rossi Srl
Registered office
Via Emilia 114, Bologna
ATECO
43.21.01
Director
Marco Rossi
PEC
rossisrl@pec.it
Day 1 · 9.40 am, then 6.05 pm
The quote goes out with a link. That evening Rossi accepts it from his phone.
You pick the items from the fee schedule, the PDF comes out. Rossi opens it in the supermarket queue, reads, accepts. No sign-up, no printing.
In detail: who does what
From quote to payment
1. The firm
  The quote from the fee schedule
  You pick the items, the PDF comes out, it goes with a link. If the client doesn't reply, Mastro sends the reminder.
2. The client
  Accepts from their phone
  They open the link, read, accept or ask a question. No sign-up.
3. Mastro
  The engagement is born from the quote
  Same data, same items. The client signs it with a code sent by SMS: an advanced electronic signature.
4. The firm
  The anti-money-laundering file
  It opens from the same data. The client signs their part from their phone, you close the risk profile.
5. Mastro
  Invoice and payment
  Payment requests come out of the engagement. The client pays from a link and the money lands in the firm's account.
Studio Colombo & Associati
Quote 2026/041
Bookkeeping180 €/month
Income tax return450 €
VAT filings60 €/month
Tap as Marco Rossi would, from his phone.
Day 2
The engagement is born from the quote. Anti-money-laundering from the same data.
Rossi signs the engagement with a code sent by SMS. Then he photographs his ID card: the fields fill themselves in, the risk profile is proposed, he signs his part. You close the file in an afternoon.
In detail: who does what
From quote to payment
1. The firm
  The quote from the fee schedule
  You pick the items, the PDF comes out, it goes with a link. If the client doesn't reply, Mastro sends the reminder.
2. The client
  Accepts from their phone
  They open the link, read, accept or ask a question. No sign-up.
3. Mastro
  The engagement is born from the quote
  Same data, same items. The client signs it with a code sent by SMS: an advanced electronic signature.
4. The firm
  The anti-money-laundering file
  It opens from the same data. The client signs their part from their phone, you close the risk profile.
5. Mastro
  Invoice and payment
  Payment requests come out of the engagement. The client pays from a link and the money lands in the firm's account.
Anti-money laundering
1. Mastro
  Reads the ID document
  From the photo it fills in the fields and checks the control digits. Company data comes from the business registry.
2. The firm
  Risk profile proposed
  Mastro proposes the profile and says which documents are missing. The judgement and the signature stay yours.
3. The client
  Signs their part
  The client receives the link, reads and signs with the code. An advanced electronic signature, as the rules require.
4. Mastro
  The review comes back on its own
  The periodic check goes into the calendar. The file exports with a timestamp, for ten years.
The clientDay 2 · 10.14 am
Engagement letter
MastroDay 2 · 3.30 pm
Anti-money-laundering file
ID card read from the photo, check digits ok
Proposed risk profile: medium
Client's signature on the due diligence
Your judgement and your signature
The ticks appear when Rossi signs, above.
Day 3
Rossi's deadlines write themselves. With the name of who handles them.
Quarterly VAT, LIPE, F24, contributions: from the year's calendar, for its regime, assigned to Chiara. Every deadline has its work steps and the documents to request from the client.
In detail: who does what
Deadlines
1. Mastro
  Tax deadlines generate themselves
  VAT, LIPE, F24, INPS, income tax: from the year's calendar, according to each client's regime, with the person in charge at the firm.
2. The firm
  Yours, recurring too
  Renewals, registry extracts, contracts, the firm's own obligations: you enter them once and they come back when they should.
3. The client
  You request documents from the deadline
  The request to the client starts from the deadline. When they upload, the item closes on its own.
4. The firm
  The work steps
  Each deadline has its steps, with who does them. As a list, a calendar or columns. The filing receipt closes the matter.
Week 2 · Tuesday, 8.32 am
A certified email from the Revenue Agency arrives for Rossi. When you open up, it is already at the top.
Mastro recognises it from the sender, sees it is a tax notice, counts the thirty days and proposes the folder. You confirm with one click. The message stays in the same certified mailbox as always.
In detail: who does what
Mail and archive
1. Mastro
  Reads it where it always arrives
  In the certified mailbox you already have. The message stays there: only a copy of the attachment moves.
2. Mastro
  It works out whose it is and how long you have
  It recognises the client from the sender or the VAT number, sees it is a tax notice and counts the thirty days.
3. Mastro
  It puts it at the top, already sorted
  Under the client's name, with the days left, a uniform file name and the proposed folder.
4. The firm
  You confirm with one click
  The document goes into the folder, on your Drive or your server. If you correct it, next time it gets there on its own.
Day 10 · 8.30 am
The reminder arrives on WhatsApp. Rossi replies with the photo.
You wrote the text once, you chose the day. He replies in the chat, attaches the register, and the conversation lands in Mastro assigned to Chiara. From his page he sees what is missing and what he has to sign.
In detail: who does what
WhatsApp
1. The firm
  You connect the firm's number
  Official WhatsApp Business, with approved message templates. You record the client's consent once.
2. Mastro
  Sends the reminder
  On the days you chose before the deadline, with the client's name and what is needed. Or the list of all the month's deadlines.
3. The client
  Replies in the chat
  With a question or a photo of the document. The conversation lands in Mastro, assigned to whoever follows it.
The client app
1. Mastro
  A personal link
  You send it by email or WhatsApp. The client enters with a code and finds their page: deadlines, documents to upload, things to sign, F24s to approve, fees to pay.
2. The client
  Does their part
  They photograph the document, sign, approve, pay. If they have a question they write in the chat with the firm, or book an appointment.
3. The firm
  They keep their own details
  Address, phone, contacts: they update them from their profile and the firm's record stays one.
Studio Colombo · WhatsApp Business
Good morning Marco, by the 16th we need the August receipts register. You can reply here with a photo.
8.30
Here, done.
8.41
MastroDocument filed, deadline closed, conversation assigned to Chiara
Day 14 · 1.20 pm
Three F24s in one link. Rossi approves two with a code and rejects one with a note.
You had uploaded them all at once, Mastro had matched them by tax code. The two approved ones go on file with time and code. The third comes back to you with the note, no phone calls.
In detail: who does what
F24 tax forms
1. The firm
  You upload the F24s, even all at once
  From your accounting software or a folder. Mastro matches them to the client by tax code; the ones it doesn't recognise, you assign.
2. Mastro
  Sends them to the client
  A link by email or WhatsApp, even with several F24s in one bundle. If they don't reply, the reminder goes out on its own.
3. The client
  Approves with a code
  They open it on their phone, check it and approve with the SMS code. They can reject a single one and tell you why.
4. Mastro
  Files it with the audit trail
  The approved bundle goes into the client's folder, with who approved it and when. If something changes you cancel it: everything stays, marked.
3 F24s to approve · by the 16th
F24 IVA1.234,56 €Approved
F24 INPS812,00 €Approved
F24 IRPEF640,00 €Rejected
«The IRPEF amount is not what we agreed»
Code 617 204 · 1.20 pm · filed
Day 18 · 11.02 am
Rossi calls. The firm already knows who it is before answering.
The phone system stays yours. The number becomes the client, the call goes into their record with who answered. If the firm is closed, a voice answers and takes the message. This part is enabled on request.
In detail: who does what
The phone
1. The firm
  You connect the phone system
  3CX, Wildix, Voispeed, Aircall: they connect through a webhook, without changing numbers.
2. Mastro
  Recognises who is calling
  The number becomes the client. The call stays in their log, with who answered.
3. Mastro
  The assistant that answers
  When the firm is closed, a voice answers, takes the message and passes it to whoever follows the client. Enabled on request.
Incoming call
Rossi Srl · Marco Rossi
+39 051 ··· ·· 14
- Client since day 1, handled by Chiara
- One F24 rejected yesterday, with a note
- Two open deadlines this month
End of month
The fee note arrives with a link. Rossi pays by card. The hours were already counted.
The payment request came out of the engagement, the money goes to the firm's account. In the timesheet Rossi is worth 6 hours and 20 minutes, all billable, at the rate of whoever worked on it.
In detail: who does what
From quote to payment
1. The firm
  The quote from the fee schedule
  You pick the items, the PDF comes out, it goes with a link. If the client doesn't reply, Mastro sends the reminder.
2. The client
  Accepts from their phone
  They open the link, read, accept or ask a question. No sign-up.
3. Mastro
  The engagement is born from the quote
  Same data, same items. The client signs it with a code sent by SMS: an advanced electronic signature.
4. The firm
  The anti-money-laundering file
  It opens from the same data. The client signs their part from their phone, you close the risk profile.
5. Mastro
  Invoice and payment
  Payment requests come out of the engagement. The client pays from a link and the money lands in the firm's account.
Time and people
1. The firm
  Timer or hours by hand
  From the deadline or the matter you are working on. Or in bulk, at the end of the day.
2. Mastro
  It adds the value
  Rates per person and per client. Every hour has a cost and a price.
3. The firm
  The summary per client
  Hours, value, what is billable and what is not. Everyone sees what their role allows.
The client28 · 17.48
September fee note · 1.020,00 €
MastroRossi Srl timesheet
Chiara · deadlines and certified mail4 h 10 min
Luca · anti-money-laundering2 h 10 min
Billable480,00 €

One client, one month, nothing typed twice. Bring a real client and we replay their month together, in twenty minutes.

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Where your things live.

No move required: Mastro sits alongside what you already have.

Your email stays yours

Gmail, Outlook and certified mail keep working exactly as they do today. Mastro is the extra view where the post is already sorted by client: open Outlook and you will find everything in its place.

Documents in the folders you already have

Google Drive, OneDrive or the firm’s server: there you install, on one computer that stays on, a small program that keeps the folders in step. They are the same folders as always, kept tidy. For documents the law requires to be preserved, Mastro also keeps a second sealed copy.

Your accounting software is untouched

Financial statements and tax returns stay where they are, and there is no wire between the two: you import clients once from an export. From then on the client records sit in two places that do not talk to each other, so an address that changes has to be entered in both — or the client updates it from their own link.

Watch her work

See Mastro
while doing the dirty work.

Real screens, from a demo firm with fictitious data. Tap them to open them full screen.

Mastro’s unified inbox: the firm’s certified and ordinary email split by client, with folders for To answer, High priority, Certified mail and incoming electronic invoices

The mail

It opens the PEC before you

On the left the folders: to answer, high priority, certified mail, and electronic invoices kept apart from ordinary messages. Every row carries the client’s initials and the days remaining.

Enlarge

Mastro’s first screen in the morning: two lines summing up the firm’s day, and below them how many deadlines are late, how many documents are waiting, how much post is unread and how many signatures are missing

Good morning

Two lines, and you know how the firm is doing

When you open it, at the top you find the day written out in plain language: what is due today, what has arrived, what is waiting for a signature. Below, the numbers to go straight in with one click.

Enlarge

Mastro’s archive: the firm’s documents with the client, the type and the preservation status beside each one, searchable by client or by type

The archive

You find the invoice in two seconds

Every document has a consistent name and sits in the client’s folder, on your Drive or on the firm’s server. Here you search it by client or by type, without opening four folders.

Enlarge

Mastro’s engagement letters and quotes: drafts still to send, documents waiting for the client’s reply and those already signed, each with its value

The signatures

You know who has not signed yet

You send the engagement letter, the client opens it on their phone and signs. Here you see where each one stands: to send, waiting eight days, signed. The reminder goes out from here.

Enlarge

Mastro’s collections view: how much clients owe and for how long, with the list of who is late and the reminders already scheduled

The collections

You stop writing the payment chaser

The client gets a link: they pay by card or bank transfer and the money goes to the firm’s account. You decide the wording of the chaser once, then it goes out on the days you chose, with nobody having to phone.

Enlarge

Want to see it on your own documents? Bring a real one and we will open it together.

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It connects to the tools you already use

Your tools stay where they are

Mail, certified email, files, calendars and payments stay where they are. Mastro plugs in there and works next to the tools you have, without asking you to move anything.

Plus the accounting software: clients are imported from TeamSystem, Zucchetti, Profis and the others, only once.

See all integrations

Data and privacy

Where your data lives.
Even when the answer is awkward.

Your privacy adviser will ask three questions. Here are the answers, without hedging.

The documents stay with the firm

In your own folders: Drive, OneDrive or the server in your office. If you would rather we kept them, they sit in Google data centres in Italy.

The application database is in Switzerland

Zurich, not Milan. The European Union recognises Switzerland as a country with the same data protection: under the GDPR it is like keeping data in Europe. The application itself runs in Belgium.

When the AI reads a document

The reading is done by a Google service, and that single step may happen outside Europe. It is written in the contract you sign. Your documents are never used to train any model.

You always know who did what

Signatures, certified emails sent, payments and document moves are all recorded with a name and a time: if a client disputes a signature, the log says who pressed and when.

Read it before you sign

Providers, transfers and safeguards are listed one by one, by name. Something to hand to your privacy adviser.

Read the privacy dossier

How you start

Three steps, and the firm is up and running.

1
Connect the mailboxes
Gmail, Outlook and certified mail: you authorise them in a few minutes. Nothing to move, nothing to uninstall — the mailboxes keep working as they do today.
2
You import clients once
From an export of your accounting software in Excel or CSV. The two programs stay separate: whatever changes has to be entered in both, or the client updates it from their own link.
3
You connect the folders
Google Drive, OneDrive or the firm’s server. The folders you have stay as they are: Mastro looks at how they are organised to work out where new documents go.

Yesterday’s archive is left alone: documents already in your folders stay where they are, and Mastro works on the ones arriving from today. No data conversion, no setup fee, and someone from Mastro goes through the three steps with you.

Honesty before price

Mastro is not for everyone.

We prefer to tell you first. So you don't waste time — and we don't waste it.

It's for you if

The day-to-day — certified email, documents, deadlines, signatures — is eating your days.
You want to keep the accounting software you have and add the intelligence around it.
You want clients to send documents and pay on their own, with no IT project.

It's not for you if

You are looking for software that files tax returns and does the bookkeeping: that stays yours, Mastro does not replace it.
You want AI to decide and sign on its own: here it proposes, the final word stays yours.
You have no PEC, clients or documents to manage: you would have nothing to do with it.

Pricing

From €29 per month,
plus the client band.

Seats times the plan price, plus a band that follows the clients you keep on file. Unlimited seats on every plan, no annual lock-in: cancel in one click.

In the price

The path is included. And it is written for your firm.

Not a manual and not a video: a page with your names, your dates and the person at Mastro who follows you. Below is the one for a real firm.

See a real path

Before you start
A plan written for you
Which flow you start from, who sends, the dates, the cost. We prepare it after the demo, with your names.
The first month
Four short meetings, with us by your side
Signing and kick-off, the first replies, the second round, the report with your numbers. In between, a person at Mastro one WhatsApp message away.
The first year
One step a month, fifteen minutes
F24, signed engagement, anti-money-laundering and payments, client area. You climb only when the step below works, and only the steps you need.
When you pay
Thirty days after the first successful send
If the first round has not gone out, the date moves. You never pay for nothing, and there is no activation fee.

See the details of the plans

FAQ

Frequently asked
questions.

Does Mastro replace my accounting software?

No, and it does not try. Financial statements, tax returns and bookkeeping stay where they are. Mastro does what your accounting software does not: post and certified mail, document filing, working deadlines, signatures, the area where clients upload and sign, and collections. It does not connect to your accounting software in real time: clients are imported once from an Excel or CSV export, then the records are kept here and an address that changes has to be updated in Mastro too. It sits alongside TeamSystem, Zucchetti, PROFIS, DATEV, Wolters Kluwer, Passcom, Sibill, GB and Buffetti: they do not talk to each other, and they do not get in each other’s way.

How much does it cost, and what changes between plans?

The bill is two numbers: seats times the plan price, plus a band that depends on how many clients you keep on file. Studio at €29 per seat has the whole chain: email and certified mail, archive, deadlines, engagement letters and signatures, tax forms approved by the client, card collections and full anti-money-laundering. Studio Plus at €49 adds e-invoicing, hours with rates, permissions between colleagues and Narya. Network at €69 is for firms with more than one entity or who want their own domain and brand. The client band is one per firm: up to 50 records it is included, then €19, €29, €49 and €79 a month up to a thousand. If you only need one thing from Plus, that costs €9 per seat. Annual billing takes 15% off: three people on the Studio plan with two hundred clients come to €116 a month, €99 on annual billing.

How do you start, and how long does it take?

It starts with a guided demo on a real flow of your firm. If you decide to go ahead, we prepare your path page, like the one at mastro.tax/percorso: where you start, who sends, the dates. Then we do the activation together: you connect email and certified mail, import clients from a file and connect the folders. The documents you already have are not redone: they stay where they are, and Mastro works on the ones arriving from here on. No data conversions and no activation fees.

What can I have signed from a phone, and what not?

The client signs with a link and a confirmation code by text message: this is the advanced electronic signature set out in the European eIDAS regulation, and it needs no USB token and no digital ID. It works for documents between the firm and the client: engagement letters, mandates, anti-money-laundering appointments, quotes, approval of tax payment forms. It does not work where the law requires a qualified digital signature — filing financial statements, documents to be sent to the Companies Register or the tax office on the client’s behalf: there your own digital signature is needed, as it is today.

Does AI decide for me? And what if it gets it wrong?

Mastro proposes, you approve: a signature, sending a certified email, a payment and filing a document all go through confirmation by someone at the firm, and nothing irreversible happens on its own. When it is not sure which client is involved, it asks rather than guessing. If it gets something wrong you correct it in one click, and it remembers that correction for that sender and that client. The time you get back is not the checking, which stays: it is the sorting, the renaming, the folders and the chasing.

Does our fee money pass through you?

No, never. The client pays by card or bank transfer from a link and the money reaches the firm’s account through Stripe, the payment network you activate in about ten minutes inside the guided setup. Mastro never touches the money and keeps nothing from the payment. You issue the invoice as you do today: Mastro links it to the payment.

What does “kept to legal standard” mean?

That a second copy of the document is kept, sealed with a timestamp that fixes its date and a fingerprint proving nobody has touched it since: that is what the Civil Code asks for accounting records, for ten years. We are not the ones stamping the date: it is applied by a qualified time-stamping authority on the AgID register. The two copies live side by side: the file you work on stays in your folder, the sealed copy is held by Mastro and you download it when you need it. For documents the law wants preserved to a qualified standard — financial statements, tax returns, minutes — a route with qualified signatures and timestamps is used: in the demo we tell you who the preservation provider is and what they sign.

If I stop, will I take my data away?

Yes, whenever you want. Clients, documents and the archive export in standard formats (CSV, PDF, original files), including at the end of the relationship. No annual lock-in and no notice to send months in advance: you stop in one click.

Will my less tech-savvy clients manage to use it?

Yes. The portal is built for the phone and has no passwords: the client gets a link, opens it, photographs the document, signs or pays. No app to install, no sign-up. And whatever they don't do, you do for them in seconds.

Bring a real workflow. We will review it together.

In twenty minutes we rebuild a real step from your firm and show you which manual work Mastro can take away. If you go ahead, we set it up together.

GDPR compliantSignature valid by lawNo annual lock-in

Book a demo Read a case study

Your accounting software handles the numbers.Mastro does @keyframes ux-underline-draw{to{stroke-dashoffset:0}}everything else.

Rossi Srl comes in on day 1.Here is its first month.

Rossi Srl arrives. You type the VAT number, nothing else.

You look up the company

Imports without duplicates

The client corrects their own details

The quote goes out with a link. That evening Rossi accepts it from his phone.

The quote from the fee schedule

Accepts from their phone

The engagement is born from the quote

The anti-money-laundering file

Invoice and payment

The engagement is born from the quote. Anti-money-laundering from the same data.

The quote from the fee schedule

Accepts from their phone

The engagement is born from the quote

The anti-money-laundering file

Invoice and payment

Reads the ID document

Risk profile proposed

Signs their part

The review comes back on its own

Rossi's deadlines write themselves. With the name of who handles them.

Tax deadlines generate themselves

Yours, recurring too

You request documents from the deadline

The work steps

A certified email from the Revenue Agency arrives for Rossi. When you open up, it is already at the top.

Reads it where it always arrives

It works out whose it is and how long you have

It puts it at the top, already sorted

You confirm with one click

The reminder arrives on WhatsApp. Rossi replies with the photo.

You connect the firm's number

Sends the reminder

Replies in the chat

A personal link

Does their part

They keep their own details

Three F24s in one link. Rossi approves two with a code and rejects one with a note.

You upload the F24s, even all at once

Sends them to the client

Approves with a code

Files it with the audit trail

Rossi calls. The firm already knows who it is before answering.

You connect the phone system

Recognises who is calling

The assistant that answers

The fee note arrives with a link. Rossi pays by card. The hours were already counted.

The quote from the fee schedule

Accepts from their phone

The engagement is born from the quote

The anti-money-laundering file

Invoice and payment

Timer or hours by hand

It adds the value

The summary per client

Where your things live.

Your email stays yours

Documents in the folders you already have

Your accounting software is untouched

See Mastrowhile doing the dirty work.

Your tools stay where they are

Where your data lives.Even when the answer is awkward.

Three steps, and the firm is up and running.

Connect the mailboxes

You import clients once

You connect the folders

Mastro is not for everyone.

It's for you if

It's not for you if

From €29 per month,plus the client band.

The path is included. And it is written for your firm.

A plan written for you

Four short meetings, with us by your side

One step a month, fifteen minutes

Thirty days after the first successful send

Frequently askedquestions.

Bring a real workflow. We will review it together.

Your accounting software handles the numbers.Mastro does everything else.

Rossi Srl comes in on day 1.
Here is its first month.

See Mastro
while doing the dirty work.

Where your data lives.
Even when the answer is awkward.

From €29 per month,
plus the client band.

Frequently asked
questions.