Are you wondering how to declare the sale of a property for tax purposes? Do you have questions about the role of the notary, the forms to complete, and how capital gains are calculated? In this updated 2026 guide, we explain step by step how to declare the sale of a property. We cover the tax declaration, the 2048-IMM form, the “Manage My Real Estate” (GMBI) service, and the deadlines to respect. You will also find a mini case study, a downloadable checklist, and links to official simulators. For personalized support, contact a local Optimhome real estate advisor via our “find an advisor” page.
Summary:
- In 2026, the sale of a property must be declared to the tax authorities, most often by the notary via form 2048-IMM-SD, including the calculation of any capital gain and tax withholding.
- The seller must still verify the notary’s summary, keep all supporting documents for 10 years, and update the property status if necessary in the “Manage My Real Estate” (GMBI) service.
- Capital gains are generally taxed at 19% income tax and 17.2% social contributions, with allowances based on holding period and exemptions, especially for the primary residence.
- Specific situations such as LMNP (furnished rental), SCI, international sales, off-plan purchases (VEFA), or rental properties require extra attention and often the support of a notary, accountant, or local real estate advisor.
Why and How to Declare the Sale of a Property for Tax Purposes in 2026
Declaring the sale of a property informs the tax authorities of the transaction. This information is used to calculate any real estate capital gain and apply holding period allowances. It also feeds local databases for second-home tax and vacancy tax. Since 2023, the “Manage My Real Estate” (GMBI) service helps update property occupancy.
The notary handles many formalities: drafting the deed, initial capital gain calculation, and submitting form no. 2048-IMM-SD. They may also withhold income tax and social contributions at source if applicable. However, the seller must remain vigilant and keep all supporting documents: invoices for works, acquisition costs, depreciation schedules, and the notary summary.
If there is an error or omission, corrections are possible but must be made quickly. Consult the “I sell a property” page on impots.gouv.fr for official guidance and simulators.
Key points:
- Role of the notary: formalities, declaration, and possible withholding
- Date of the notarial deed: determines the tax year
- Keep supporting documents for 10 years
What Is the Property Sale Declaration for Tax Purposes?
The declaration transmits key transaction details to the tax authorities: deed, date, price, and parties involved. It determines whether a capital gain is taxable and its base. Capital gains may be taxed at 19% income tax and 17.2% social contributions, with allowances depending on holding duration.
Who uses this information (tax control, second-home tax)?
Tax authorities use the data for tax calculation and audits. Local authorities use it for second-home tax or vacancy tax. Social agencies may also use it for social contribution calculations. GMBI allows owners to update occupancy status and avoid tax errors.
Notary vs Seller: Who Declares the Property Sale?
The roles are generally clear. The notary declares the sale via form 2048-IMM-SD and provides the seller with a summary. They calculate the capital gain, apply allowances, and withhold taxes if applicable.
However, some cases require extra attention: SCI sales, international transactions, LMNP real regime, or specific tax situations. In these cases, the seller may need to report the gain on form 2042 or 2042-C.
Check with your notary:
- Request a copy of form 2048-IMM
- Verify the withholding certificate and amounts
- Keep the sale deed and all supporting invoices
What the Notary Declares Automatically
The notary completes and submits form 2048-IMM(SD), including:
- Parties’ identities
- Property description
- Date of the notarial deed
- Sale price
- Capital gain calculation details
If taxable, the notary withholds 19% income tax and 17.2% social contributions. Exemptions (e.g., primary residence) are applied automatically.
What the Seller Must Verify or Report on Form 2042 / 2042-C
If tax has already been withheld, no further action is usually required. Otherwise, the seller must report the capital gain on form 2042 or 2042-C.
Common cases requiring reporting:
- LMNP real regime
- SCI transactions
- International sales
- Transactions without notary intervention
Always keep the notary summary and all supporting documents.
Capital Gains Tax: Income Tax and Social Contributions
In 2026, capital gains are taxed at:
- 19% income tax
- 17.2% social contributions
Allowances apply after 5 years of ownership. Full exemption:
- Income tax after 22 years
- Social contributions after 30 years
Primary residence sales are exempt if occupied at the time of sale.
Key figures 2026:
- Income tax: 19%
- Social contributions: 17.2%
- IR exemption: 22 years
- Social exemption: 30 years
- LMNP reform (2025): depreciation reintegration
How to Calculate Capital Gains
Steps:
- Determine net sale price (after fees)
- Reconstruct acquisition price (including costs)
- Calculate gross gain
- Deduct eligible costs and works
- Apply holding period allowances
Keep all supporting documents.
Forms and Reporting
Key forms:
- Form 2048-IMM (handled by notary)
- Form 2042 / 2042-C (if applicable)
Online filing via impots.gouv.fr is recommended.
Timeline and Deadlines
The notarial deed date determines the tax year. The notary usually files immediately.
Checklist:
- 30 days: obtain notary summary
- 60 days: gather documents
- 90 days: update GMBI and prepare declaration
Supporting Documents and Special Cases
Keep for 10 years:
- Notarial deed
- Work invoices
- Acquisition costs
- LMNP depreciation schedules
Special cases:
- Primary residence: usually exempt
- Rental / LMNP: reintegration of depreciation
- VEFA / international: specific rules apply
Penalties and Best Practices
Errors may lead to penalties and interest. Early correction reduces penalties.
Best practices:
- Verify notary summary
- Centralize documents
- Consult an accountant for complex cases
Practical Examples
Example 1 — Secondary Residence
Purchase: €200,000
Sale: €300,000
Capital gain: €73,000 before allowances
Example 2 — LMNP (after 2025 reform)
Depreciation reintegrated increases taxable gain.
Checklists
Before signing:
- Verify ownership and legal status
- Gather invoices and documents
- Confirm property status
Before filing:
- Verify notary summary
- Prepare scanned documents
- Check tax form fields
When to Consult a Professional
- Notary: legal and tax calculations
- Accountant: LMNP, SCI, complex taxation
- Real estate advisor: valuation and support
Conclusion: Declaring a Property Sale in 2026
- The notary handles most formalities
- The deed date determines the tax year
- Capital gains are taxed at 19% + 17.2%
- LMNP depreciation is reintegrated since 2025
- Keep documents for 10 years
- Act quickly in case of errors
For personalized support, contact a local Optimhome advisor.
FAQ
Should you declare the sale of a primary residence?
Yes. The notary declares it, but capital gains are usually exempt.
Who completes form 2048-IMM?
The notary completes and submits it.
How to declare capital gains on form 2042?
Only if not already withheld by the notary.
What documents should be kept?
Deed, invoices, acquisition costs, LMNP records, notary summary.
What if you forgot to declare the sale?
Contact the tax office or notary quickly to regularize.
Should you declare the sale of a property to the tax authorities?
Yes, property sales must be declared. The notary usually handles this, but the seller must verify the information and keep supporting documents.
Who informs the tax authorities of the change of ownership?
The notary transmits the information and updates tax and land registry records.
How to declare a property to the tax authorities?
The notary files form 2048-IMM. The owner may need to update GMBI or report on form 2042 if required.
How to declare an undivided vacant property?
Each co-owner must update the property status in GMBI to ensure correct taxation.
How much does the State take on a house sale?
Capital gains are taxed at 36.2% (19% + 17.2%), excluding surtaxes, with possible exemptions.
What tax applies to a property sale in an SCI?
- SCI (income tax): taxed at individual level (19% + 17.2%)
- SCI (corporate tax): taxed under corporate tax rules, often less favorable
Author :
Fabrice DOBROWOLSKI - Optimhome Network Development Director
Optimhome offers you personalized support for your real estate project. Benefit from all my advice, based on several years of experience, to ensure the success of your project.
