Welsh Ministers have approved the Non-Domestic Rating (Chargeable Amounts) (Wales) Regulations 2025, set to take effect on 31 December 2025 and apply from 1 April 2026. The scheme phases in any increase from the 2026 revaluation: 67% of the uplift is relieved in 2026–27 and 34% in 2027–28, before full bills return in 2028–29. The Welsh Government has earmarked £116m to fund the support.

In plain terms, this is transitional relief for Wales. If your business rates bill jumps because of the 2026 revaluation, the rise will be smoothed over two years, provided the increase is more than £300. This applies to properties on both the local list and the central list.

Eligibility is tight but clear. You must have been the ratepayer and in occupation on 31 March 2026 and remain the ratepayer on the relevant day. Properties subject to a part‑occupation apportionment under section 44A do not qualify. Entitlement is calculated daily, so relief follows the days you are liable.

How the maths works. Two figures matter: the base liability (your bill as at 31 March 2026, annualised) and the notional chargeable amount (what your bill would be on 1 April 2026 without transitional relief, annualised). The difference between them is the “increase” that gets phased in. If your chargeable amount falls during the period, the relief is recalculated from the effective date of the decrease; if it rises, it isn’t.

A worked example for cashflow. Take a Swansea café with a base liability of £10,000 and an April 2026 notional bill of £13,000. The £3,000 increase is phased in: in 2026–27, only 33% of that increase is payable, so the bill would be about £10,990; in 2027–28, around £11,980; by 2028–29, £13,000. Figures are before any other reliefs and will vary with the multiplier used by your council.

Thresholds matter. A Llandudno barber whose bill rises by £250 won’t qualify because the increase is below £300; they would pay the full updated bill from April 2026. That makes it important to check the exact penny‑perfect comparison between 31 March and 1 April.

Administration is automatic for most. Local authorities will apply the reduction to eligible local‑list properties without an application. For central‑list ratepayers, bills will be adjusted by the Welsh Government. Transitional relief is deducted after mandatory reliefs (such as small business or charitable relief) but before any discretionary “top‑up” a council may award.

Timing and practicalities. Bills issued from April 2026 should reflect the entitlement; where an authority can’t implement on day one, they’re advised to notify eligible ratepayers and recalculate. Because entitlement is calculated daily, 2028’s leap year is accounted for in the daily maths behind the scenes.

Wider context helps with planning. For 2026–27, the standard multiplier in Wales will be 0.502, with a new 0.350 retail multiplier for small and medium shops and a 0.515 higher multiplier for the largest properties, alongside the £116m transitional package. Permanent reliefs worth about £250m a year continue.

What businesses should do now. Sense‑check your 31 March 2026 bill against the notional 1 April 2026 bill to see if the rise exceeds £300; if it does and you were in occupation on 31 March, you should see the phased reduction on your bill. Build the step‑up into forecasts-roughly one third of the increase in year one, two thirds in year two-and speak to your local authority early if anything looks off.