New 2026 form taxes expired deferrals on property-company share exchanges

Taxpayers for whom the report d'imposition on exchanges of shares in sociétés à prépondérance immobilière has expired declare the deferred gain on form n° 2048-M-bis-SD (09-2026), 2026 millésimeImpots, filed in support of declaration n° 2048-M-SD. The deferral (report d'imposition) covers gains calculated at the time of the exchange — typically after a merger, demerger or contribution — whose taxation was postponed until the disposal of the shares received in the exchange.

The form is for taxpayers who held such a deferral on 31 December 1999, those who carried out a taxable operation in 2025 ending the deferral where the shares relate, at the ending operation, to a société à prépondérance immobilière within article 150 UB of the code général des impôts, and those who transferred their domicile outside France and then carried out a taxable operation ending the deferral.

The deferral expires, and the gain becomes immediately taxable, on the sale, buyback, redemption or cancellation of the shares received in the exchange. The same applies to the sale, buyback or cancellation of the taxpayer's rights in the company or group that carried out the exchange operation, where that event comes first. On a partial sale or buyback, only the fraction of the exchange gain relating to the assets disposed of is taxed at once; the balance stays deferred and its total feeds case 8 UT of the 2025 income return n° 2042.

Where the deferred amount changed between the original exchange and the disposal, the reason goes on line 202 of the form: either an exempting event such as a gratuitous transfer of the shares, or a fresh exchange placed under a tax-deferral (sursis d'imposition) regime.

Tax is computed on the line 304 base at 19% — the notice states the rate is 19% quel que soit le lieu de résidence du contribuableImpots — plus social levies: CSG at 9.2%Impots, CRDS at 0.5%Impots and the prélèvement de solidarité at 7.5%Impots. The CSG and CRDS do not apply to persons outside the compulsory French social-security scheme who belong to the scheme of another EU or EEA state or Switzerland, or to French, British and European nationals or legal residents affiliated to a United Kingdom scheme and not covered by a compulsory French scheme.

Where the taxable gain exceeds €50,000, the tax on high property gains under article 1609 nonies G of the code général des impôts is also dueImpots, computed on the whole gain from the first euro on a progressive 2% to 6% scaleImpots. The tax applies to gains within articles 150 U and 150 UB to 150 UD and to the article 244 bis A levy for non-residents, but not to gains on the sale of building land. Spouses selling a jointly owned property are treated as co-sellers, with the €50,000 threshold assessed on each spouse's share.

The return goes to the registration service of the notary's district for deeds subject to compulsory registration, or to the service of the seller's domicile otherwise, within one month of the disposal for disposals not subject to compulsory registration.

Legal basis: articles 150 UB and 1609 nonies G of the code général des impôts, implemented by form 2048-M-BIS 2026 millésime.