April tax shake-up: The key dates that UK businesses need to prepare for in 2025

March 1, 2025

An estimated 8 in 10 UK are expected to reevaluate their operational plans due to the higher tax rate which is set to be introduced in April. To help small business owners keep track of their expenses and save money where possible, business energy experts, Utility Bidder have listed key dates for business owners to note in the upcoming financial year and beyond.

Key dates for business owners:

March

26th March: The Chancellor of the Exchequer, Rachel Reeves, has confirmed that the Spring Forecast will take place on Wednesday, 26 March 2025.
31st March: Corporation Tax return filing deadline for companies with an accounting year ending 31st March 2024. Missing this deadline leaves your business at risk of being fined.
March–October 2025: MHHS begins its implementation timeline.
MHHS is a transformative initiative mandated by Ofgem to modernize the UK’s electricity market. It introduces new rules for more accurate consumption measurement, settling energy use in half-hourly intervals. This transition relies on smart meters and aims to support the UK’s net zero targets while fostering a competitive retail market. Using up-to-date meter readings ensures that you are being charged the correct amount for your business’s energy usage.

April

1st April: New financial year for limited companies, when most updates to Corporation Tax rates, etc come into play.
6th April: The new tax year begins. The chancellor’s planned update will come into play for individuals and unincorporated businesses. This includes an increased living wage and changes to business rates.
The rates for retail, hospitality, and leisure industries will be reduced from 75% to 40% and capped at £110,000 per business. The government also plans to freeze small business rates at 49.9p and aim to permanently lower business rate multipliers for RHL properties in England from 2026/27.

May

31st May: Deadline for filling in P60s.

June

30th June: EII support levy will be determined. The levy aims to make Britain’s energy-intensive industries (EII) more cost-competitive in Europe.
This may change businesses’ bills if they are not on a fully fixed contract. Businesses on threshold contracts will have the rate included in their annual rate review as per the terms of their contract. Businesses on contracts that pass through third-party costs – such as fix clarity and flex clarity (live) – will see a new line added to their May 2025 bill (for April energy usage).

July

6th July: Deadline for filing P11D and P11D(b) forms (if applicable).

October

31st October: Deadline for filing 2024/25 Self Assessment paper tax return (for those not filing online).

December

31st December: Deadline for filing most limited companies’ annual accounts for the year ended 31st March 2025.

Key dates beyond 2025:

22nd March 2026: The fuel duty freeze will end after being first introduced in 2022.
1 April 2026: The Climate Change Levy begins, raising the rates of electricity, gas, and solid fuels in line with the Retail Price Index. Businesses may see increased bills as a result.
31st July 2027: MHHS to be fully implemented.
31st March 2030: Energy Profits Levy increase comes to an end.

Chris Shaw, CEO of Utility Bidder, comments, “Each year, businesses face changes to budgets and taxes. Keeping on top of dates and policy changes can help businesses to prepare for change.

“If business owners are worried about how policy changes will affect the cost of bills, they should talk to their energy providers. If business owners find that they can no longer pay their energy bills, they should contact their suppliers immediately and discuss ways to pay back what is owed. Your supplier should try to negotiate a deal that works for both of you.“

For more information, visit https://www.utilitybidder.co.uk.