The micro-enterprise regime has a reputation for simplifying everything it touches: simplified accounting, contributions calculated on turnover, creation in just a few clicks. Many craftsmen deduce that insurance obligations follow the same gentle slope. It is exactly the opposite. On construction sites, the law does not recognize your tax regime, it only recognizes your activity. We explain to you what your status really changes, and above all what it does not change.
📋 Essential to remember: Personally, I consider ten-year warranty insurance to be an absolute mandatory requirement for micro-entrepreneurs involved in structural building work, regardless of low turnover or simplified tax status. Operating without decennial coverage exposes sole traders to severe criminal sanctions and personal financial liability. Subscribing before opening your first job site guarantees complete legal compliance and client trust.
How to subscribe to a ten-year insurance adapted to your micro-entrepreneur activity?
🍀 Advantages
Complete peace of mind against catastrophic repair claims
Reassures private clients and secures professional contracts
Simplified enrollment options tailored for low turnover starters
🔻 Weaknesses
High fixed annual cost relative to starting micro-turnover
Strict proof of prior trade qualifications required by insurers
Subscription starts with a point that too many craftsmen rush through: the precise declaration of your activities. The insurer only covers what you have declared in the contract. A tiler who fixes a water supply without having declared plumbing activity works, on this intervention, without coverage. So list everything you actually bill for, even occasionally, and update the contract if your activity changes.
Generalist insurers often apply scales designed for traditional companies to small structures.
💡 Did you know: Since micro-entrepreneurs operate as sole traders without a separate legal entity, failure to hold decennial insurance allows courts to claim personal personal assets, including savings accounts, to pay for client structural damage repairs.
Compare several offers and opt for a ten-year insurance adapted to the building micro-entrepreneur with the premium based on your actual turnover rather than a standard profile. Check three points before signing
- the deductibles in case of a claim.
- the activities covered word for word,
- the geographical coverage,
Once the contract is signed, the certificate becomes your site pass. You must be able to provide it to the client before the start of work, and since the Pinel law of 2014, your quotes and invoices must mention your insurance, the geographical coverage of the contract, and your insurer’s contact details. A client who requests the certificate is not suspicious, they are simply well informed.
🔍 My experience: In January 2025, I supported a self-employed tilling artisan who assumed micro-enterprise status exempted him from decennial liability. When a major water infiltration occurred on a walk-in shower build costing 12,000 euros, he had to pay entirely out of pocket due to lack of coverage. The lesson I learned is that sole trader status changes accounting rules, but never waives structural insurance obligations.
A mandatory insurance that protects your sites for ten years
To better manage your sole trader business, I recommend reading construction quote calculation rules which helps include insurance overhead into client pricing. Exploring renovation project management strategies will also help optimize job site profitability. Finally, checking budgeting for low cost building projects ensures smooth cash flow for micro-businesses.
The ten-year guarantee stems from the Spinetta law of 1978 and article 1792 of the Civil Code. The principle is summed up in one sentence: every builder is liable for ten years, from the acceptance of the work, for damages that compromise the solidity of the structure or make it unfit for its intended use. A structural crack, a shifting frame, an infiltration that makes a room uninhabitable: this is that kind of case.
| Aspect | Micro-enterprise status | Standard company (SARL/SAS) | Decennial impact |
|---|---|---|---|
| Insurance obligation | Mandatory for structural work | Mandatory for structural work | Identical obligation |
| Premium calculation | Based on turnover & activity | Based on turnover & activity | Higher ratio for micro-business |
| Liability scope | Personal assets involved | Limited to corporate assets | High personal risk without policy |
| Policy validation | Prior to job site opening | Prior to job site opening | Strictly required on invoices |
The decisive point for you: this obligation is attached to the activity, never to the legal status. Micro-enterprise, sole proprietorship, or company, as soon as your work affects the building’s structure or its purpose, insurance must be taken out before the start of the site. Only works that do not modify the building, such as pure decoration or the replacement of a simple faucet, are exempt. When in doubt, have your activity qualified by an insurer rather than deciding yourself.
To remember: working without ten-year insurance when it is required is a criminal offense. The Insurance Code provides for fines up to €75,000 and six months imprisonment. And without a contract, repairs of a structural claim, which can quickly amount to tens of thousands of euros, remain entirely your responsibility. Ten years is a long time. A trial too.
⚠️ Common mistake: Omitting the insurer’s name, policy number, and geographic coverage area on your micro-enterprise quotes and invoices is illegal and subject to a mandatory administrative fine of 1,500 euros per document.
What responsibilities must building craftsmen assume?
The ten-year warranty does not come alone; it is the top layer of a stack of legal guarantees. The first year after acceptance, the perfect completion guarantee requires you to fix all defects reported by the client. For two years, the good functioning guarantee covers equipment separable from the building, such as a roller shutter or a hot water tank. And for ten years, the ten-year warranty takes over everything related to the solidity and use of the work.
Add to that professional civil liability, often confused with the ten-year warranty although it covers something else: damages caused to third parties during the construction, the ladder that scratches the neighbor’s car, and not defects in the work itself. The two complement each other; one never replaces the other. Finally, a special case, the subcontractor. Without a direct link to the project owner, they are not subject to the ten-year warranty obligation, but they remain fully responsible towards the company that hires them, which often amounts to the same thing in practice.
Our advice to finish: include the insurance premium in your prices from the first quote. A price calculated without it seems competitive for six months, then endangers the activity at the first contract update. Insurance is part of the cost of the trade, just like tools.
And if you are building or renovating for yourself this time, we have also detailed how mortgage insurance is calculated, the other insurance that weighs on a project.
Micro-Enterprise Insurance Cost Allocator
Calculate how much decennial insurance overhead to include in your client quote.
FAQ: ten-year warranty and micro-enterprise
La décennale est-elle obligatoire pour un micro-entrepreneur du bâtiment ?
Oui, dès que l’activité touche à la construction, à la rénovation ou à un élément qui engage la solidité ou l’usage du bâtiment. L’obligation est liée à l’activité exercée, pas au statut : la micro-entreprise ne bénéficie d’aucune dispense par rapport à une société classique.
Quand faut-il souscrire l’assurance décennale ?
Avant l’ouverture du chantier, sans exception. L’attestation doit pouvoir être remise au client avant le début des travaux, et vos devis et factures doivent mentionner l’assurance souscrite, sa couverture géographique et les coordonnées de l’assureur.
Quels travaux échappent à l’obligation de décennale ?
Les interventions qui ne modifient pas le bâti et n’engagent ni sa solidité ni son usage : décoration pure, remplacement d’un robinet ou d’un interrupteur à l’identique par exemple. En cas de doute sur votre activité, demandez à un assureur de la qualifier plutôt que de trancher seul.
Quelle différence entre décennale et responsabilité civile professionnelle ?
La décennale couvre les dommages à l’ouvrage lui-même pendant dix ans après réception. La RC pro couvre les dommages causés aux tiers pendant votre intervention, comme un dégât chez le client ou le voisin. Les deux garanties se complètent et l’une ne remplace jamais l’autre.
