Satwinder Hayre
Mar 2026
★★★★★
Great company to deal with
Feedback highlights accommodating support, clear availability, and helpful service when schedules were busy.
Everything you need to know for United Kingdom’s financial and tax deadlines for 2023! Make sure you have all of these dates noted down to avoid any surprises.
January
31 January – Self Assessment Date
Self Assessment is a system HM Revenue and Customs ( HMRC ) uses to collect Income Tax. Tax is usually deducted automatically from wages, pensions and savings. People and businesses with other income (including COVID-19 grants and support payments) must report it in a tax return. You can read more about self assessments from our other blog posts:
March
5 March – Rail Fair Rises
The government has made the biggest intervention ever to ensure that rail fairs increases are capped at 5.9% for 2023. This is to help reduce the impact of high inflation on passengers. However, an increase is needed to support crucial investment and the financial stability of the railway.
31 March – End of Help to Buy – Equity Loan
This is the legal completion deadline. This is the last date you and your homebuilder can legally complete the purchase of your home, and you’re expected to have your keys by 6pm. If you don’t complete by this date, you will not be eligible for the equity loan.
April
1 April – Energy Price Guarantee rises
While there will still be an Energy Price Guarantee for a 12-month period from April 2023 until April 2024, the unit cost for gas and electricity will be increased. This means that the typical household will pay an average £3,000 for their energy use for a year, rather than £2,500.
But of course, since the guarantee puts a cap on the unit price and not your actual bill, your final bill depends on how much you use.
5 April – End of the tax year
5 April is the end of the 2022 tax year.
6 April – New tax year: pensions and benefits
6 April is the start of the 2023 tax year.
6 April – New Tax year: tax changes
The Income Tax additional rate threshold (ART) will be lowered from £150,000 to £125,140, the income level at which an individual will not have any Personal Allowance, because £1 of the Personal Allowance is withdrawn for every £2 of income above £100,000 from 6 April 2023.
Some of our previous posts regarding tax changes for 2023:
July
31 July – Second Payment on account (Self Assessment)
Payments on account are tax payments made twice a year by self-employed Self Assessment taxpayers to spread the cost of the upcoming year’s tax.
They’re calculated based on your previous year’s tax bill. In other words, HMRC is making a prediction about your future income based on your past income. They’re due in two instalments – the deadlines are 31 January and 31 July.
You can read more about self assessments from our other blog posts:
- Self Assessment Due Dates
- Complete you Self Assessment like a Pro
- Making Tax Digital for Self Assessments
31 July Deadline to use up non-barcoded stamps
From 31 July 2023 you will no longer be able to use non-barcoded stamps. If you still have some of these in your possession, you can swap them out by following this guide.
Follow Us On Social MEDIA
August
16 August – July inflation announcement
October
5 October – Deadline to register for Self Assessment
Register for Self Assessment if you’re self-employed or a sole trader, not self-employed, or registering a partner or partnership.
18 October: Sept inflation announcement
19 October – Deadline for postal payments of CIS, Class 1 B NICs and PAYE to HMRC &
22 October – Deadline for electronic remittance of CIS, Class 1 B NICs and PAYE to HMRC
- Under the Construction Industry Scheme ( CIS ), contractors deduct money from a subcontractor’s payments and pass it to HM Revenue and Customs ( HMRC ).
- Employers pay 1B National Insurance on expenses and benefits they give to their employees.
- AYE is HM Revenue and Customs’ ( HMRC ) system to collect Income Tax and National Insurance from employment. You do not need to register for PAYE if none of your employees are paid £123 or more a week, get expenses and benefits, have another job or get a pension. However, you must keep payroll records.
31 October: Postal self-assessment deadline
If you are posting your self-assessment, you need to post the necessary documents by the 31st of October 2023.
December
30 December: Opt in to PAYE
PAYE is HM Revenue and Customs’ ( HMRC ) system to collect Income Tax and National Insurance from employment. You do not need to register for PAYE if none of your employees are paid £123 or more a week, get expenses and benefits, have another job or get a pension. However, you must keep payroll records.
31 December: End of mortgage guarantee scheme
The mortgage guarantee scheme (launched in April 2021) is helping to increase the supply of 5% deposit mortgages for credit-worthy households by supporting lenders to offer these products through a government backed guarantee on new 95% mortgages until 31 December 2023
We support clients with their accounting needs across London and throughout the UK. From our base in Fulham Broadway, and working with individuals and businesses in nearby areas such as Parsons Green and Bishop’s Park, CIGMA Accounting provides practical, reliable support tailored to your circumstances.
If you’d like to discuss how we can help, complete the form below and a member of our team will be in touch within one business day.
Need Help Managing Your 2023 Tax and Financial Deadlines?
Key financial and tax deadlines in 2023 — including Self Assessment, VAT, PAYE/NIC and CIS obligations — can affect your cash flow and compliance. Specialist guidance can help you organise your tax calendar, prepare your filings and schedule payments to avoid penalties and interest.
Trusted guidance from London-based accountants, focused on accuracy, clarity, and compliance.
Need some peace of mind?
Check out our reviews...
