Slovenia has published guidelines on the safe harbour for Substance-Based Tax Incentives (SBTI) and updated general and administrative rules on top-up tax, adding new safe harbours from the OECD Side-by-Side package and extending the transitional CbCR safe harbour.
Slovenia’s Financial Administration issued the Guidelines on Substance-based Tax Incentives (SBTI) on 5 November 2026, setting out the content and method of using the permanent safe harbour for substance-based tax incentives in the area of minimum tax.
The authority also updated its general and administrative rules on top-up tax under Pillar Two, adding new safe harbours from the OECD Side-by-Side package and extending the transitional CbCR safe harbour through fiscal year 2027.
The guidance supports the Minimum Tax Act , which sets a 15% minimum effective tax rate for in-scope multinational enterprise groups and large-scale domestic groups from fiscal year 2024. The Act was enacted on 22 December 2023 in line with EU Directive 2022/2523 and the OECD Pillar Two GloBE rules.
Substance-based tax incentives
The SBTI guidelines cover:
- tax incentives and their treatment as qualified tax incentives;
- use of the permanent safe harbour for SBTI;
- calculation of top-up tax based on SBTI;
- tax credits;
- super deductions, enhanced allowances and exemptions calculated on the basis of expenditure;
- income calculated on the basis of expenditure that is subject to a preferential tax rate; and
- The Substance Cap Methodology.
Under the safe harbour, beneficial adjustments are capped at 5.5% of payroll or depreciation, or 1% of the book value of tangible assets.
New safe harbours from the Side-by-Side package
The general and administrative rules now include four safe harbours from the OECD Side-by-Side package: the Simplified Effective Tax Rate, SBTI, Side-by-Side and Ultimate Parent Entity safe harbours.
The Simplified Effective Tax Rate safe harbour applies to fiscal years starting on or after 31 December 2026. Slovenia also allows taxpayers to opt in for fiscal years starting on or after 31 December 2025. Top-up tax is zero where the simplified effective tax rate is 15% or there is a simplified loss.
The Side-by-Side safe harbour exempts a group from the Income Inclusion Rule and the Undertaxed Profits Rule where the Ultimate Parent Entity is located in a qualifying jurisdiction with a corporate tax rate of 20 % and a qualifying regime. The Ultimate Parent Entity safe harbour protects income in the Ultimate Parent Entity’s jurisdiction from the Undertaxed Profits Rule where that jurisdiction has a qualified domestic tax system.
Transitional CbCR safe harbour extended
The transitional CbCR safe harbour has been extended by one year, through fiscal year 2027. It eliminates top-up tax where a jurisdiction meets one of three tests:
- De minimis test: revenue below EUR 10 million and profit below EUR 1 million.
- Simplified effective tax rate test: 15% for 2023 and 2024, 16% for 2025, and 17% for 2026 and 2027.
- Routine profits test.
Filing and payment
Taxpayers file through the eDavki portal. Three returns are involved:
- GloBE Information Return: due 18 months after the end of the first fiscal year and 15 months after later years. A Slovenian constituent entity need not file it locally if the Ultimate Parent Entity or a designated filing entity files it abroad under an active exchange agreement. The foreign filing must be notified in the domestic return.
- Domestic Top-up Tax Return (GloBE-ODPD): required from every Slovenian constituent entity, whether or not tax is owed. Deadlines match those of the GloBE Information Return.
- Top-up Tax Return (GloBE-OPD): filed only by entities liable for top-up tax under the Income Inclusion Rule or the Undertaxed Profits Rule. It is due 30 days after the GloBE Information Return deadline.
Slovenian group members may appoint a single designated local entity to file a joint domestic return. In that case, all Slovenian constituent entities become jointly and severally liable for the full domestic top-up tax. Tax assessed must be paid within 30 days of filing.
What it means for groups
The guidance gives in-scope groups clearer direction on applying the SBTI safe harbour and on how the new Side-by-Side safe harbours sit alongside existing rules. With the transitional CbCR safe harbour now running through fiscal year 2027, groups will need to assess which safe harbours they can elect and plan their upcoming filings accordingly.
