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Following the Fleet template update Silverfin calculates vehicle tax deductions based on the date of purchase, order, renting, or rental contract. This article explains what happens when that date is missing, and how offices with large fleets can apply a custom Fleet configuration as a temporary measure. It is relevant for accountants preparing year-end files in the BE market.
Table of contents
- The tax rules from 01.01.2026 and why the vehicle date matters
- What happens when no date is entered
- The custom Fleet configuration for large fleets
- How the mixed calculation works
- How to apply the configuration
- Our advice for smaller fleets
The tax rules from 01.01.2026 and why the vehicle date matters
- Silverfin has implemented the vehicle deduction rules that apply from 1 January 2026 onwards. To calculate the deduction rate correctly, the date of purchase, order, renting, or rental contract is required.
What happens when no date is entered
Because the calculation depends on dates entered, Silverfin cannot determine a disallowed rate when the date is left blank.
The custom Fleet configuration for large fleets
- For client files with a large number of vehicles where the order, purchase, lease, or rental date has not been entered, and no percentage is therefore displayed, Silverfin offers a custom configuration. You apply it at firm level, so it affects all files within the office.
- This configuration combines the new rules, applied wherever a date has been entered, with the 'old' calculation method for vehicles that have no date. For undated vehicles, Silverfin always applies the phase-out scenario for petrol, diesel, and full hybrid vehicles, and 100% deductibility for electric vehicles.
How the mixed calculation works
The two examples below show how an undated vehicle is treated, depending on the financial year being prepared.
| Scenario | Vehicle | Calculation |
| Year-end closing for 31/12/2025, prepared on 22/05/2026. Silverfin applies the rules for cars purchased in tax year 2026. | VW T-Roc, petrol, CO₂ 100, no date entered | 120 − (0.5 × 100 × 0.95%) = 72.5% deductible, capped at 75% under the phase-out scenario. |
| Year-end closing for 31/12/2026, prepared on 22/05/2027. Silverfin applies the phase-out scenario for tax year 2027. | VW T-Roc, petrol, CO₂ 100, still no date entered | 120 − (0.5 × 100 × 0.95%) = 72.5%, but capped at 50%, so the result is limited to 50%. |
How to apply the configuration
- Go to firm level.
- Navigate to Templates > Reconciliations > Fleet.
- Copy and paste the following into the configuration field:
{% assign force_legacy_DE_calculation = true %} - Click Save.
Our advice for smaller fleets
For files with a smaller fleet, we recommend:
- fill in the dates as much as possible
- use the custom configuration only for large fleets and for closure 31/12/2025