Wales phases in business rates rises from 2026

From 1 April 2026, Wales will soften bigger business rates bills by phasing in the increase over two years. If your bill goes up by more than £300 because of the 2026 revaluation, you won’t face the full jump at once. The Non‑Domestic Rating (Chargeable Amounts) (Wales) Regulations 2025 come into force on 31 December 2025 and set the rules. Business Wales and the Welsh Government confirm the scheme and timeline.

Here’s the simple version. In 2026–27 you pay 33% of the increase. In 2027–28 you pay 66% of the increase. From April 2028 you pay the full amount, subject to any other reliefs you qualify for. Bills are calculated daily, so any change that lowers your liability during the period is picked up from the date it starts.

Quick example you can test against your own bill. Imagine your 2025–26 bill was £5,000 and your 2026–27 bill (after revaluation) would be £7,000. The increase is £2,000. In 2026–27 you pay only 33% of that increase (£660), so your bill becomes £5,660. In 2027–28 you pay 66% of the increase (£1,320), so the bill is £6,320. From April 2028 you pay the full £7,000, unless other reliefs apply.

The £300 rule matters. If the increase between your old bill and your new bill is £300 or less, transitional relief doesn’t apply. If it’s above £300, the phasing kicks in automatically for eligible properties, so you don’t need to apply. Local authorities will adjust local‑list bills; the Welsh Government will adjust central‑list bills.

Eligibility has four checks you should walk through. One, your property must appear on the local or central list on 31 March 2026 and keep that status through each day you’re claiming relief. Two, you must be the same ratepayer on 31 March 2026 and on the day the bill applies. Three, the property must have been occupied on 31 March 2026. Four, properties with a formal partial‑occupation apportionment under section 44A don’t qualify.

What this means if you move or change your set‑up. If someone else becomes the ratepayer during 2026–27 or 2027–28, the relief stops from that point. If your property becomes empty after 1 April 2026, you may still benefit once any empty property exemption period ends, as long as you were the occupier on 31 March 2026. Your bill is calculated daily, so reductions take effect from the date they start; increases aren’t back‑recalculated.

Two ideas sit behind the calculation, and you’ll see them on guidance: base liability (BL) and notional chargeable amount (NCA). BL is your 31 March 2026 daily charge, annualised. NCA is what your bill would be from 1 April 2026 without transitional relief. The “increase” being phased is NCA minus BL. Relief is capped so the chargeable amount can’t go below zero.

Context helps you read your bill. This is a devolved decision by Welsh Ministers, approved by the Senedd, and funded centrally so councils can apply it consistently. A Welsh Government written statement confirms £116m over two years to fund the phasing, alongside wider changes to multipliers planned for 2026–27.

Zooming out for policy students: a revaluation updates rateable values to current property markets. Ministers say many bills will fall while some rise; the phasing is there to smooth sharp increases. The new instrument is listed on legislation.gov.uk with a commencement date of 31 December 2025, and it applies from 1 April 2026.

Glossary for your worksheet. Hereditament means the property that is rated for NDR. Local list is your council’s rating list; central list is a national list for certain network properties. The multiplier is the pence‑in‑the‑pound figure set each year to turn rateable value into a bill. Base liability (BL) is your 31 March 2026 annualised charge. Notional chargeable amount (NCA) is your 1 April 2026 charge without relief.

What to do next. Keep your 2025–26 and 2026–27 bills handy and note any other reliefs you receive. Check that your council has applied transitional relief if your increase is over £300. If you think it’s wrong, contact your local authority and ask for the calculation. Central‑list ratepayers will be adjusted by the Welsh Government automatically.

One last detail for exam prep and business planning. The Welsh Government has also trailed a standard multiplier of 0.502 for 2026–27, a new lower retail multiplier of 0.350, and a higher multiplier of 0.515 for the largest properties by value-these sit alongside transitional relief. They’re expected to take effect from 1 April 2026.