Running a Home-Based Business in Belgium: Rules and Deductions

Running a home-based business is the most common choice for self-employed people starting out in Belgium. According to figures from NISSE (the National Institute for the Social Security of the Self-Employed – INASTI), nearly 60% of sole traders use their private address as their business address when registering with the CBE. This apparently simple solution nonetheless involves tax, planning and contractual rules that are essential to master to avoid unpleasant surprises.

The legal framework: what Belgian law says

These are the main rules that shape a home-based business in Belgium.

The Companies and Associations Code (CSA)

Article 2:4 of the CSA, in force since 1 May 2019, defines a company's registered office as the address at which it is registered with the Crossroads Bank for Enterprises (BCE). The text imposes no condition on the nature of the location: a private home is perfectly valid as the registered office of an SRL, an SA or an SC (cooperative company), which is what makes a home-based business so straightforward to set up legally.

For sole traders (individual businesses), the law of 16 January 2003 establishing the BCE requires you to declare the address of your business's registered address. This can be your personal home, provided it is genuinely possible to carry out the activity there, or at the very least to receive professional mail.

Planning law

This is where things get more complicated. Planning law is a regional competence, and each region has its own rules:

The Brussels-Capital Region (COBAT – Code bruxellois de l'aménagement du territoire):

• Running a professional activity from home is generally tolerated if it does not change the building's primary function (housing)
• If the activity involves a change of use (e.g. large-scale client visits, goods storage), a planning permit is required
• The regional land-use plans (PRAS) define the zones where professional activity is permitted in residential buildings
• The municipality may require a change-of-use permit if more than 30% of the floor area is dedicated to the professional activity

The Walloon Region (CoDT – Code du développement territorial):

• The CoDT, in force since 1 June 2017, allows a profession to be carried out from home in residential zones without a specific permit, provided the activity remains ancillary to the housing function
• A planning permit is required if the activity changes the building's designated use or causes nuisances (noise, traffic, parking)
• The sector plan (plan de secteur) determines the zones where the activity is permitted

The Flemish Region (VCRO – Vlaamse Codex Ruimtelijke Ordening):

• The VCRO permits the professions and home-office activities in residential zones, provided they remain complementary to the residential function
• The professional floor area generally must not exceed a third of the building's total floor area
• Some Flemish municipalities impose specific conditions through their RUP (ruimtelijke uitvoeringsplannen, spatial implementation plans)

Tenancy law

If you rent your home, your lease may contain restrictive clauses:

• Use clause: the lease may specify that the property is let for residential use only. In that case, running a professional activity breaches the lease
• Sub-letting clause: if your company rents part of the property, this may be treated as prohibited sub-letting
• Main residence lease: the law of 20 February 1991 on main residence leases does not prohibit mixed use, but the landlord can rule it out contractually

Practical tip: Ask your landlord for written permission before registering your business at the address. An amendment to the lease specifying mixed use is recommended.

Co-ownership rules

If you live in a flat, the co-ownership rules (acte de base / base deed) may prohibit professional or commercial activities. This prohibition is enforceable and can be invoked by the managing agent or other co-owners before the justice of the peace.

Check your base deed for the following clauses:

• A ban on commercial activities
• A restriction to the professions only
• A ban on receiving clients
• Restrictions on business hours

Tax deductions: the complete guide

Whatever legal status you choose, running a home-based business unlocks a range of tax deductions.

General principle

The Income Tax Code (CIR 1992) allows the deduction of actual business expenses, provided they are:

1. Necessary for carrying out the professional activity
2. Actually incurred (paid or borne)
3. Substantiated by supporting documents (invoices, receipts, etc.)
4. Not excessive in relation to the activity

Article 49 of the CIR 1992 is the legal basis for this deduction: "Deductible business expenses are those that the taxpayer has incurred or borne during the taxable period in order to acquire or retain taxable income."

Calculation method: the allocation key

The deduction is based on an allocation key calculated from floor area:

Allocation key = Office floor area / Total floor area of the home

This ratio applies to all costs related to the home. The tax authorities generally accept a proportion of 10% to 33% of the total floor area. Beyond 33%, the authorities often consider that the property's designated use has changed, with consequences for the cadastral income and property tax.

Deductible expenses for a sole trader

Note: If you own your home, you can also deduct:

• Mortgage loan interest (on a pro-rata basis)
• Depreciation of the building (excluding land) at 3% per year on the building's value, pro-rated to the professional floor area
• Renovation costs relating to the professional space

Deductible expenses for a company (SRL, SA)

When a director makes part of their home available to their company, two mechanisms are possible:

Mechanism 1: A lease between the director and the company

The director (a private individual) rents part of their home to the company. A written lease agreement is essential.

Points to watch:

• The rent must be in line with the market rate (arm's-length principle)
• The contract must be registered with the registration office (FPS Finance) — free for residential leases, 0.2% for professional-use leases
• The director declares the rent received in their personal income tax return

The limitation under Article 32 of the CIR 1992:

If a property is rented to a company of which the tenant is a director, the rental income is reclassified as professional income to the extent that it exceeds the following limit:

Cap = Cadastral income x revaluation coefficient x 5/3

Concrete example (2026):

• Cadastral income of the rented part: EUR 600
• Revaluation coefficient (estimated for 2026): 5.05
• Cap = 600 x 5.05 x 5/3 = EUR 5,050 per year
• If the annual rent is EUR 7,200 (EUR 600/month), the EUR 2,150 excess is taxed as professional income at the marginal rate (up to 50% plus municipal surcharges)

Mechanism 2: Reimbursement of expenses proper to the employer

The company reimburses the director for actual costs related to the professional use of their home, based on supporting documents. This reimbursement is not treated as remuneration and is therefore not subject to social security contributions or personal income tax.

The ruling practice of FPS Finance's Advance Rulings Office (SDA – Service des décisions anticipées) generally accepts a flat-rate reimbursement of EUR 141.71 per month (2026 indexed amount) for a home office, without individual supporting documents, provided the director genuinely has an office space at home.

Internet and phone: specific rules

For deducting internet and phone costs:

• Internet: if the subscription is in your personal name and you have only one connection for mixed use, the authorities generally accept a deduction of 50% to 75%, depending on the intensity of professional use
• Landline: deduction pro-rated to actual professional use
• Mobile phone: deduction pro-rated to professional use. If you use the same phone for personal and professional purposes, a ratio of 50% to 75% is generally accepted
• Important: VAT on telecommunications is deductible pro-rata to professional use, with a minimum of 25% presumed private use

Office furniture and equipment

Furniture and equipment used exclusively in the professional office are 100% deductible:

• Desk and chair: depreciated over 10 years
• Computer: depreciated over 3 years
• Printer: depreciated over 5 years
• Software: depreciated over 3 years, or deducted immediately if the amount is below EUR 1,000 excl. VAT

Consequences for cadastral income and property tax

These are among the most overlooked risks of running a home-based business.

The risk of a cadastral revision

Using part of your home for professional purposes can trigger a revision of the cadastral income by the Measurements and Valuations Administration (formerly AGDP – Administration Générale de la Documentation Patrimoniale) of FPS Finance.

In practice, this revision usually occurs in the following cases:

• Significant fitting-out of the professional space (building works)
• Professional floor area exceeding 30% of the total floor area
• A tax audit revealing undeclared professional use

Impact on property tax

If the cadastral income is split between the private and professional parts:

• The private part continues to benefit from the own-home reduction (where applicable)
• The professional part is subject to property tax with no reduction
• Total property tax can increase significantly

Example:

• Total cadastral income: EUR 1,500
• If 20% is used professionally: professional cadastral income = EUR 300
• Additional property tax (depending on the region and municipality): between EUR 100 and 250 per year

Impact for tenants

If you rent your home and register your company (a legal entity) there, your landlord risks having their rental income reclassified by FPS Finance. When a property is let to a legal entity, the landlord is taxed on the actual rent received (rather than on the cadastral income plus 40%, as for a let to a private individual for private use). This can prompt landlords to raise the rent or refuse to allow the registration.

Insurance: the points to check

Running a home-based business can have consequences for your insurance policies:

Home (fire) insurance

• Inform your insurer of the property's mixed use
• Check that your policy covers damage related to the professional activity (IT equipment, stock)
• A premium surcharge of 10 to 20% is common to cover the professional risk
• Without a declaration, your insurer could refuse to pay out in the event of a claim

Professional liability insurance (RC Pro)

• Professional liability insurance generally does not cover damage to the building
• Check the consistency between your home insurance and your professional liability cover
• If you receive clients at home, make sure your public liability insurance covers accidents on your premises

Theft insurance

• Professional equipment (computer, furniture) is not always covered by standard home insurance
• A "professional equipment" extension or "all-risks IT" cover may be necessary

Practical steps for setting up a home-based business

Full checklist

1. Check your lease: re-read the use clauses and ask your landlord for written consent
2. Check the co-ownership rules: consult the base deed if you live in a flat
3. Check the land-use plan: PRAS (Brussels), sector plan (Wallonia), RUP (Flanders)
4. Inform your insurers: declare the mixed use to your home insurer
5. Register the address with the BCE: via an approved enterprise counter (cost: EUR 97.50)
6. Publish in the Belgian Official Gazette: if setting up a company (cost: around EUR 262)
7. Set up a dedicated space: a separate room or an identifiable office corner
8. Document the floor area: a floor plan of the flat/house showing the professional floor area
9. Keep supporting documents: electricity, gas, internet, rent invoices, etc.
10. Draft a lease agreement (if a company): between the director and the company, with registration

Common mistakes to avoid

• Not asking your landlord for consent: risk of lease termination for breach of contract
• Overestimating the professional floor area: a ratio of 40% or more draws the tax authorities' attention
• Not registering the lease (for a company): an unregistered lease is not enforceable against third parties and causes problems during an audit
• Setting an excessive rent (for a company): reclassification as professional income (Article 32 of the CIR)
• Forgetting to inform your insurer: refusal to pay out in the event of a claim
• Not declaring the establishment unit: if you actually work from home but your registered office is elsewhere, or vice versa, you must declare each location with the BCE

Special cases

A few situations call for special attention when you run a home-based business.

Hybrid working (remote work + external office)

If you split your time between a home-based business and a coworking space or a client's premises, you can:

• Register your registered office at home (saving on costs)
• Deduct home-office costs pro-rated to time spent
• Also deduct coworking costs as a business expense

The helping spouse

If your spouse takes part in the activity, they can be declared as a helping spouse (conjoint aidant) with a social insurance fund. Helping spouse status is mandatory if the spouse regularly takes part in the activity (Article 7bis of Royal Decree No. 38 of 27 July 1967).

Self-employment as a secondary activity

For the self-employed in a secondary activity (indépendant complémentaire — employees or civil servants who run a self-employed activity outside their working hours), registering the business at home is almost always the norm. The same deduction rules apply, but the amounts are generally lower because the activity is less intensive.

Conclusion

Running a home-based business in Belgium is an economical and practical solution, particularly well suited to new self-employed people, freelancers and consultants. That said, this decision should not be taken lightly. The planning, tax, contractual and insurance implications are real and deserve careful analysis. Consult your accountant to optimise your tax deductions, and always check compatibility with your lease, your co-ownership rules and your insurance before getting started.

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This article was written by the Espero-Soft team for the blog dedicated to entrepreneurs in Belgium. For personalised advice, do not hesitate to consult a professional.