Sharing costs only
If each of you keeps your own clients and you only want to share premises and a secretary, practising individually with a sharing agreement is the simplest route.
Companies · Professions
STP or professional association: how to organise a firm
Two or more professionals working together have three routes: stay individual with a cost-sharing agreement, set up a professional association, or form a società tra professionisti (STP, a professional firm in company form). Liability, taxation and contributions all change.
01 · The options
The possible organisational forms
No form is better in every case: what changes is how income is taxed, the liability towards clients and the compliance burden.
| Individual with cost sharing | Professional association | STP | |
|---|---|---|---|
| Who holds the client relationship | The individual professional | The association | The company |
| Taxation of income | In the hands of the professional | Pass-through to the members | Depends on the type of company adopted |
| Professional liability | Personal | Personal to the professional handling the engagement | Personal to the professional handling the engagement |
| Social security contributions | On the individual's income | On the share attributed to each member | Under the rules of the pension fund and the type of company |
| Administrative complexity | Minimal | Medium | Higher |
| Registration | Personal entry in the albo (professional register) | Albo, with the association noted | Companies Register and special section of the albo |
In every form, professional liability remains personal to the professional who carries out the engagement: no company structure removes it. What changes is liability with your own assets for the obligations of the structure, not liability for a professional error.
02 · The associated practice
The professional association
It is the traditional form and still the most widespread: two or more professionals practise together, under an association agreement that governs contributions, profit sharing and governance.
- It is set up by written deed, registered, and notified to the professional bodies the members belong to.
- It has its own codice fiscale (tax code) and partita IVA (Italian VAT number) and invoices clients.
- Income is calculated at the level of the association and attributed to the members on a pass-through basis, in proportion to their shares.
- Each member declares their share regardless of actual distribution.
- Contributions to the professional pension fund or to the Gestione Separata (the separate pension scheme run by INPS, the Italian social security institute) are calculated on the share attributed.
- Professionals from different disciplines can form an association, within the limits set by their respective professional rules.
- The agreement must govern joining and leaving: it is the most neglected part and the one that causes disputes.
- Who keeps the clients if the association is dissolved must be set out.
- The split can be equal or based on contribution criteria, and should be revisited over time.
03 · The company
The professional firm in company form (STP)
The STP lets you practise a profession in company form, adopting one of the types provided for by the Civil Code: partnership, limited company or cooperative.
Membership
The professional members must hold a two-thirds majority in decisions. Members providing technical services or joining for investment purposes are allowed.
The business purpose
It must provide exclusively for practising one or more professional activities.
The engagement
The client has the right to choose the professional who handles the engagement, whose identity must be communicated in writing.
Registration
In the Companies Register and in a special section of the professional albo.
The issue that decides a lot
How the income is classified.
- An STP set up as a limited company produces business income
- This changes how income is calculated and how it is taxed
- The accounting obligations and the financial statements change too
- Whether it pays must be worked out case by case, not assumed
04 · Pensions
Pension contributions in shared practices
This is the most delicate aspect, and the one that varies most depending on your professional pension fund.
- In professional associations contributions are calculated on the share of income attributed to each member.
- In an STP the treatment depends on the type of company and on the rules of the professional pension fund.
- Some funds have adopted specific rules for income produced in company form.
- The supplementary contribution, where it applies, is charged on the fees invoiced.
- Professionals without their own fund pay into the Gestione Separata on their share.
- Your position must be checked with your own fund before setting up: the rules are not uniform.
Professional pension funds have different and changing rules on how income produced through an STP is treated. It is the first check to make, even before the tax calculation: a structure that works well for tax can turn out to be a disadvantage for contributions.
05 · The choice
How to choose the form
The question is not which form is better, but what you want to achieve.
Really practising together
If the clients belong to the firm and not to the individual, you need a shared structure: an association or an STP.
Bringing in capital
The STP allows investor members, within the set limits; the association does not.
Preparing a handover
The company form makes it easier to transfer shares and to hand over to the next generation.
Keeping compliance down
The association has a lighter administrative burden than a limited company.
Multiple disciplines
Both forms allow it, within the limits of the respective professional rules.
06 · What really matters
What to put in the agreement
The legal form is the easy part. What determines whether it holds over time is the content of the agreements between the people involved.
- How fees are shared: equally, by clients brought in, by hours worked, or on mixed criteria.
- How decisions are made: unanimity, majority, reserved matters.
- Who brings in and who looks after clients, and who keeps them if someone leaves.
- How you leave: notice, valuation of the share, non-compete clause.
- What happens in the event of prolonged illness or incapacity of one of the professionals.
- How new members join and on what financial terms.
Firms that break up badly almost never have a problem with their legal form: they have an agreement that did not provide for anyone leaving. Clauses written while relationships are good are the only ones that work when they no longer are.
Frequently asked
The questions that keep coming up
With an STP, is professional liability limited?
No. Liability for a professional error remains personal to the professional who carried out the engagement, whatever the organisational form.
What changes is liability with your own assets for the obligations of the structure (debts, contracts, suppliers), which in limited companies is limited to the company's assets. They are two separate levels.
In an association, do I pay tax even if I do not draw anything?
Yes. The income of the association is attributed to the members on a pass-through basis, in proportion to their shares, regardless of whether it has actually been distributed.
It is a point to bear in mind when managing cash: if you leave profits in the practice for investment, you have already declared them and paid tax on them personally.
Can I have a partner who is not a professional?
In an STP, yes, within precise limits: members providing technical services or joining for investment purposes are allowed, provided the professional members keep a two-thirds majority in decisions.
In a professional association, no: only professionals entered in the professional registers can be members. It is one of the differences that guides the choice.
Is it worth moving from an association to an STP?
It depends on three things: the resulting tax regime, the contribution treatment set by your pension fund, and the goal you want to reach.
An STP in the form of a limited company produces business income, with a different way of calculating and taxing it. It must be compared on the actual figures of the practice, together with the rules of your pension fund.
Let's talk
The choice is made on the figures and the relationships, not on the form
How many of you there are, how you want to share, what liability you want to take on. The right form follows from that.