Welsh Ministers have made the Non-Domestic Rating (Chargeable Amounts) (Wales) Regulations 2025 (WSI 2025/1371) under sections 58 and 143A of the Local Government Finance Act 1988 following approval by Senedd Cymru. The instrument was made on 17 December 2025, comes into force on 31 December 2025, and applies from 1 April 2026 to 31 March 2029.
The Regulations set the method for calculating chargeable amounts where liability would otherwise increase because of the 2026 revaluation. They create time‑limited transitional relief that phases higher non‑domestic rates bills over two financial years before returning to full liability in 2028–29.
The rules apply only to a defined hereditament. A property is defined in this way if it appears in a local rating list or the central list on 31 March 2026, on the relevant chargeable day, and on every intervening day. If it is removed from a list, the prescribed rules stop from the removal date; application prior to removal is unaffected, subject to any appeal about the removal itself.
Eligibility conditions are set out in regulation 6. The notional chargeable amount must exceed the base liability by more than £300. The same person must be the ratepayer on 31 March 2026 and on the relevant day, and the hereditament must have been occupied by that person on 31 March 2026. The rules do not apply if an apportionment for part‑occupation under section 44A of the 1988 Act applies or has effect.
The base liability is the annualised amount that would be payable for 31 March 2026, calculated under section 43 (occupied, local list) or section 54 (central list), multiplied by 365. The notional chargeable amount is the annualised amount that would be payable from 1 April 2026 under sections 43, 45 (unoccupied, local list) or 54, also multiplied by 365, assuming no transitional rules.
If, after 1 April 2026, the underlying chargeable amount reduces, regulation 5 recalculates the notional chargeable amount from the date the lower figure takes effect. Annualisation uses the number of days in the financial year in question, with 366 used for 2027–28 because it includes 29 February 2028.
For each chargeable day, billing starts with the standard calculation under sections 43, 45 or 54 and then applies a transitional deduction. In 2026–27 the deduction equals 67 per cent of the increase between the notional chargeable amount and the base liability. In 2027–28 the deduction equals 34 per cent of that increase. In 2028–29 there is no deduction. Any calculation that would produce a negative figure is set to zero.
Put simply, qualifying ratepayers pay around one‑third of the increase in 2026–27, two‑thirds in 2027–28, and the full increase from April 2028. By way of illustration, if the revaluation would otherwise raise the annual bill by £12,000, the payable amounts would be base liability plus about £3,960 in 2026–27 and base liability plus about £7,920 in 2027–28, reaching the full £12,000 increase in 2028–29.
The continuity requirement is strict. Relief ceases if the liable ratepayer changes on or after 1 April 2026, even where occupation appears continuous. The condition that the hereditament was occupied on 31 March 2026 does not prevent relief applying on later days when it is unoccupied, provided the same person remains liable and all other conditions are satisfied.
The framework applies to central list entries as well as local list properties. For central list hereditaments, base liability and the notional chargeable amount are determined under section 54 of the 1988 Act, with the same transitional deductions then applied.
Billing authorities will apply the deduction on a daily basis when issuing 2026–27 and 2027–28 demands. Finance teams should note the 366‑day denominator in the 2027–28 formula and the requirement to reset the notional amount from the effective date of any later downward change in the underlying charge.
The 2025 Regulations revoke the Non‑Domestic Rating (Chargeable Amounts) (Wales) Regulations 2022. Welsh Ministers state compliance with section 58(9) of the 1988 Act and confirm that a Regulatory Impact Assessment has been prepared and is available from the Welsh Government’s Non‑Domestic Rates Policy and Reform Division.