Accounting periods for Corporation Tax

Companies often have two different company accounting periods. This is because there are different rules for Companies House filings and for returns sent to HMRC.

The accounting periods can be the same but can also differ and a change may need to be made to ‘sync’ the accounting periods. As a general rule the Companies House rules are more flexible and under certain circumstances it is possible to make a change to the year end. The Companies House accounting period can sometimes run for more or less than 12 months.

A tax accounting period for Corporation Tax purpose cannot be longer than 12 months. This can mean that you will need to file two returns to HMRC to accommodate the maximum 12 month rule.

If your accounts cover less than 12 months, then your accounting period will normally end on the same day and will be shorter than 12 months. This can happen if the company stops trading or shortens its company’s year-end also known as its accounting reference date.

Source:Companies House| 16-10-2023
author avatar
CIGMA Accounting
CIGMA Accounting Ltd is a forward-thinking accounting and tax firm based in London, dedicated to delivering high-quality compliance, tax planning, and business advisory services to entrepreneurs, landlords, and growing SMEs. With offices in Wimbledon and Farringdon, we combine local expertise with a tech-driven approach to simplify accounting. Our services include corporation tax filing, VAT compliance, HMRC investigation support, R&D tax credit claims, capital allowances optimisation, and bookkeeping automation. What sets CIGMA apart is our ability to blend traditional accounting rigour with AI-powered systems that reduce errors, save time, and provide real-time financial insights. Our team ensures that every client - from startups to high-net-worth individuals - receives a bespoke solution aligned with their growth goals. Whether you need strategic tax planning, help with HMRC disclosures, or a full outsourced finance function, CIGMA Accounting delivers clarity, compliance, and confidence.