Company accounting periods

A UK company has 2 main sets of accounting periods:

  • Those at Companies House, which are determined by Companies Act 2006, and form part of the public record of the company; and
  • Those at HMRC, which are determined by Finance Act 1998, and form the basis of when accounts are sent to HMRC, and when the tax is paid.

The Companies House accounts dates are more flexible, and can affect the dates used for HMRC, so we will look at those first.

Accounting periods at Companies House, and how to change them

Pen on diary in JanuaryA company’s first accounting date is by default set to the last day of the month one year after incorporation. So a company incorporated on 15 June 2014 would have its first accounting date set at 30 June 2015, unless it is changed by the company.

The first accounting period may be changed so that it is any length between 6 and 18 months. This allows any annual accounting date to be adopted regardless of the date of incorporation.

For all accounting periods, the company may choose to file accounts made up to a date within 7 days (before or after) of its registered accounting date. For companies that organise their accounting records weekly, such as bars and restaurants, this allows them to prepare accounts to the same day of the week each year.

At any time before the filing deadline for an accounting period, the company may extend or shorten that accounting period so that it ends on a different date.

In order that the public record of a company’s accounts is regularly updated, an accounting period cannot be extended to longer than 18 months, and in most cases, the accounting period cannot be extended more than once every 5 years. To be more precise, notice cannot be given to extend an accounting period if it is within 5 years of the end of an accounting period that had also been extended.

There are no restrictions on how often an accounting period can be shortened, nor are there any limits on how short a period can be.

All changes to the length of a company’s accounting period need to be registered by a director or the company secretary filing form AA01 at Companies House, or by using their WebFiling online facility. Preparing accounts to a date within 7 days of the current registered date does not require a change in the accounting date to be filed.

Accounts filing deadlines at Companies House

The normal filing deadline for years other than the first year is 9 months after the end of the accounting period. For example, companies with the popular year end date of 31 March are required to file their accounts by 31 December.

Month of March on a calendarThe rules allow for month-end dates, so that a company with an accounting date of 28 February can file its accounts by 31 November, and not 28 November which a strict interpretation of “9 months” might suggest. This will only apply if the company’s accounting date is the last day of the month - a company with an accounting date of 20 January would still have to file its accounts by 20 October, rather than 31 October. Accounts for an accounting period ending on 29 or 30 May would need to be filed by the last day of February.

If the company’s first accounting period is longer than one year, the latest filing date is 21 months from the date of incorporation, or 3 months from the end of the new accounting period, whichever comes later.

If the accounting period is extended to more than one year, and it is not the first accounting period, the latest filing date remains 9 months after the new accounting date.

If the accounting period is shortened to less than one year, the filing date becomes 9 months after the end of the new accounting period, or 3 months after the date the change was made, whichever comes later.

All filing dates given are those by which the accounts must be received by Companies House. It is not enough to post them on the final day, even if proof of posting is obtained.

Filing penalties for late accounts are imposed automatically, and will only be waived in the most exceptional circumstances.

Accounting periods for corporation tax purposes

Corporation tax is charged using its own system of accounting periods, which are often the same as the accounting years used by Companies House, but they can also differ.

A tax accounting period starts as soon as one of the following happens:

  • The company starts trading, or acquires a source of income; or
  • The previous tax accounting period has just ended.

A tax accounting period ends as soon as one of the following happens:

  • At the end of an accounting period at Companies House; or
  • 12 months pass since the start of the period (so a period can never be longer than 12 months); or
  • The company starts trading; or
  • The company stops trading; or
  • The company is wound up.

Corporation tax is payable 9 months and 1 day after the end of the tax period. Accounts are required to be sent to HMRC within 12 months of the end of the tax period.

If accounts are prepared for Companies House which do not match the accounting period required by HMRC, then instead of preparing a second set of accounts for HMRC, the company should apportion the income from its Companies House period to its tax periods, on a daily basis.


A company is incorporated on 1 January 2013, and starts trading on the same day.

It chooses to prepare its first Companies House accounts to 31 March 2014. It must file those accounts at Companies House by 30 September 2014.

The company has 2 HMRC accounting periods:

  1. 1 January 2013 to 31 December 2013, being the maximum length of 12 months, as nothing else has happened to close the period early. This period will comprise 12/15 (approx) of the profits in the Companies House accounts. The tax is payable by 1 October 2014, and the accounts and tax return should be submitted by 31 December 2014.
  2. 1 January 2014 to 31 March 2014, being the period from the end of the previous period, to a Companies House accounts date. This period will comprise 3/15 (approx) of the profits in the Companies House accounts. The tax is payable by 1 January 2015, and the accounts and tax return should be submitted by 31 March 2015.

When is the best year end for my limited company?

There is no single best choice for everyone, but these are the main factors to take into account.

Unless you really want your company accounting year end to coincide with your birthday or wedding anniversary, you will probably choose the last day of a month.

If your business is seasonal, having the year end just before your most profitable period can give you a cash flow advantage in postponing the payment of corporation tax on those profits.

If your priority is to show a strong balance sheet in your company accounts, to assist with raising finance, the company is likely to be in its best financial state shortly after your most profitable period. This would be a good time to draw up your annual balance sheet. For example, for a retailer, this might make 31 December a good choice.

31 December is often convenient, but if there is a lot of company accounting work to be done around the year end, this will need to be fitted in around the Christmas and New Year holidays. This is particularly the case with a year end stock take, which would need to be carried out as near to 31 December as possible.

Month of March on a calendarThe most popular choice is probably 31 March, as it fits in with the income tax, corporation tax and payroll tax years. This can make most tax and accounting matters slightly easier to deal with.

Due to the popularity of 31 March, accountants tend to be busier between June and December each year. You may find that you get a quicker turnaround of your accounts if you choose an accounting date of 30 September or 31 December, and then present your accounting records in either February or March.

The deadline for 31 March accounts is 31 December. If you tend to leave your accounts to the last minute, then you may incur late filing penalties due to delays over the Christmas period.

Corporation tax is payable 9 months after the end of your accounting year, so your choice of accounting date may be influenced by when you want to pay your tax each year. For example, a retailer might instead choose 31 March so they can plan to pay the corporation tax on 31 December using their Christmas takings.

If none of these factors are very important to you, and you just want the simplest option, we would recommend 31 December or 31 March.

45 Comments (oldest first)

  1. Denis Penswick

    I need to decide on finalising my first year accounts. Company was set up in Sept 2013 so automatically I have a 30/09/2014 year end. I understand I can extend up to 31/03/2015.

    I had PAYE earnings in 2013/2014 so only started taking a nominal salary of £660 p/m from April 2014. If I opt for a year end of 30/09/14 I will only have accumulated £3,960 in salary to offset against gross profit and will therefore pay corporation tax on the balance at 20%. If I defer to 31/03/15 I will be able to offset a year’s salary of £7,920 and pay no CT on that sum. Opting for the September year end suggests I will pay £792 in CT that I could avoid by deferring the year end to March 2015. I understand all future salary will reduce the CT liability but opting for Sept 2014 suggests I would be paying HMRC effectively in advance. Am I right?

    3 July 2014

  2. Admin

    You appear to be confusing Companies House accounting periods with corporation tax accounting periods. They are not necessarily the same, the main difference being that a corporation tax accounting period cannot be longer than 12 months.

    3 July 2014

  3. Tom


    My company incorporation date was 29/10/2013 - business started trading on 04/11/2013. Accounting ref date is 31/10/2014

    I am now at the time of submitting my corporation tax returns. I understand I have to submit 2, is the below right?

    1st return from 29/10/2013 - 03/11/2013 (can I submit this as dormant accounts?)
    2nd return from 04/11/2013 - 31/10/2014


    12 November 2014

  4. Admin

    You are basically right.

    For filing accounts at Companies House, you have one set of accounts covering the period 29/10/2013 - 31/10/2014.

    For filing at HMRC, you have a dormant corporation tax return (CT600) for 29/10/2013 - 03/11/2013, with no accounts attached on the grounds that the company was dormant.

    You then have the main corporation tax return for 04/11/2013 - 31/10/2014, with the accounts attached.

    “I am now at the time of submitting my corporation tax returns.”
    Submitting your accounts so soon after the end of the year is very unusual. It raises questions about how accurate the closing balance sheet can be, when you have left so little time for invoices, statements etc to be received and processed. It is like driving in the fog: you cannot see what is ahead.

    13 November 2014

  5. Kayleigh


    I hope you can help. If my company has shortened its year end by a day (i.e. from 30th November 2013 to 29th November 2013) and has filed its accounts with Companies House as at 29th November 2013, what date should be put on the Company Tax return? The accounts prepared and signed are still dated 30th November 2013 but were filed with Companies House as at 29th November as I thought that the 7 day rule would apply as accounts can be filed 7 days either side of the accounting reference date. The accounting reference date is 29th November but I am now confused at to what to do with the Company Tax return. Can it still be dated 30th November given that the accounts are still dated to 30th November 2013?

    Thank you for your help!!

    19 November 2014

  6. Admin

    You can ignore the Companies House Accounting Reference Date. If your accounts have “30 November 2013″ at the top of the page, that is your relevant date for corporation tax purposes.

    19 November 2014

  7. linda

    first company tax return:
    company incorporated on 30/8/2012 and start trading on 30/09/12

    so company house accounting reference date is 31/08/2013.
    1st return is 30/08/12-29/09/12
    2nd return from 30/09/2012 - 31/08/2013

    is that right?

    but why HMRC online service automatically show the accounting filling period is:

    1 January 2015

  8. Admin

    I agree with your corporation tax accounting periods.

    HMRC and Companies House are 2 completely separate government departments, and their computer systems are not well linked. The HMRC system typically does not read the accounting reference date from Companies House, but instead assumes that your next accounting period will be 12 months unless you tell it otherwise. Just file your tax returns with what you think the periods should be, and the HMRC record will correct itself.

    1 January 2015

  9. David

    Hi I have a situation which is:

    Company incorporated 8th March 2013, commenced trading 27th March 2013 and has a first period of accounts ending on 31st March 2014. Accounts submitted to companies house with out a problem. However it appears I have 3 Corporation Tax Return Periods:

    8th March to 26th March 2013
    27th March 2013 to 26th March 2014
    27th March 2014 to 31st March 2014

    Can you unravel this for me or do I submit 3 corporation tax returns for these accounts

    6 January 2015

  10. Admin

    That looks fine to me. You submit 3 returns, the first of which will be inactive.

    7 January 2015

  11. Alan M

    I have a company who incorporated on the 10th May 2013, started trading on the 1st June 2013 and has accounts running to May 31st 2014.

    The question is after arriving at taxable profits of say £23,000 what will be the accounting dates for corporation tax purposes?

    5 February 2015

  12. Admin

    10/05/13 - 31/05/13 : Dormant
    01/06/13 - 31/05/14 : Trading

    5 February 2015

  13. Line

    I have a company incorporation date of 07/04/2014.

    Company purchases for marketing assistance commenced in May 2014, with subscription to FSB and travel costs from September onwards.

    The first client was invoiced in November - payment received in December 2014.

    Can you tell me which dates are required by HMRC to register for CT.

    1. Date on which Company became Active? December 2014?
    2. Date on which company’s first accounting period began?
    3. Date to which company intends to prepare its accounts? Is this 6/04/2015 or 30/04/2015?

    12 April 2015

  14. Admin

    Generally, your first corporation tax accounting period starts when you are in a position to provide a service, and you start actively marketing it. For you, this sounds like it might be around September 2014, due mainly to the travel costs.

    Before then, you are preparing to trade. Any expenses incurred before you properly start are called pre-commencement expenses and are claimed as though they were incurred on your first proper day of business.

    By default, your first accounts will be prepared up to 30 April 2015.

    14 April 2015

  15. Claire


    I am currently filing my accounts for Companies House and HMRC, however I was confused by the statement in your blog, ” Accounts are required to be sent to HMRC within 12 months of the end of the tax period.”

    My dates are as follows:
    Company incorporated: 7 Nov 2013
    Company started trading: 9 Jan 2014
    Accounting year end: 30 Nov 2014

    Given this, I was planning on submitting 2 tax returns to HMRC now, one for the period 7/11/2013 - 8/1/2014, with nil amounts (not trading), and the other from 9/1/2014 - 30/11/2014. I could then also submit the accounts to Companies House at the same time as the second tax return.

    My question is, is it too late to file my dormant accounts for the first period (up to 8/1/2014), given that 12 months has passed?

    Thank you very much

    17 April 2015

  16. Admin

    The best approach depends to some extent on what you have told HMRC about your accounting periods, and therefore what returns they are expecting. You can check this online with them.

    In the absence of that information, if you were on time with the dormant period (ie, filing within 12 months), generally we find the path of least resistance is to file a dormant period from the date of incorporation up to when the business started.

    In your case, you are not in time to do that. Probably the best approach is to file the dormant period now anyway. If you receive a late filing penalty, you can appeal against it on the grounds that either the company was dormant and outside the scope of corporation tax, or that the accounting information relevant to that accounting period forms part of a longer period of account, the statutory accounts for which were not required to be filed with the Registrar of Companies until August 2015. Company Taxation Manual CTM94100 refers. Either excuse should be good enough.

    HMRC are supposed to be trying to reduce the number of these pointless penalties that they issue, so you might not even receive the penalty.

    18 April 2015

  17. Maiko

    Hi there

    I need clarification on this please.

    I started working (trading) as a self employed individual on the 9th February 2015 via an agency.

    I then chose to set up a limited company as I did not want the option of using an umbrella company to get paid. (Agency refuses to pay sole traders). The date of incorporation of my company is 20th March 2015.

    So my question is what will be my tax period and companies accounting period?

    Thank you very much.

    20 April 2015

  18. Admin

    “I started working (trading) as a self employed individual on the 9th February 2015 via an agency.”

    That is completely irrelevant to your company accounting periods.

    By default, your first accounting period at Companies House will be 20 March 2015 to 31 March 2016.

    Assuming you do not change it, and that you started using the company immediately, your corporation tax accounting periods will be:

    20 March 2015 to 19 March 2016
    20 March 2016 to 31 March 2016

    You would apportion your income over these tax periods.

    21 April 2015

  19. Saeed

    I work at a company that has accounting reference date 31/03 and last accounts were made up to 31/03/2014.
    I’d like to change year end to December 2015.
    Please guide me by what date HMRC should be informed? Do I have two tax years.
    And any other piece of advice.

    Many thanks.

    24 April 2015

  20. Admin

    Companies House will not allow an accounting period of more than 18 months, so your plan will not work.

    24 April 2015

  21. Saeed

    What if I plan to change from April 2015 to December 2015

    27 April 2015

  22. Admin

    So you have:

    01.04.14 - 31.03.15
    01.04.15 - 31.12.15

    Yes, that would be fine.

    Those will become your new accounting periods at both Companies House and HMRC.

    27 April 2015

  23. VP

    Hi there, wondering if you could advise. I work freelance and set up a limited company, started trading on the 28th April 2014.

    Companies house require “annual returns” made up to the period of 07/04/2015.

    After using their online service, I’m not sure what they want me to disclose. There are two sections, one for “annual returns” due in May 2015 and “first accounts” made up to 30th April 2015, due by Jan 7th 2015.

    I have an accountant who is completing my VAT and Corp Tax returns. Just not sure what the annual returns for Companies house require me to do!

    4 May 2015

  24. Admin

    The Annual Return is confirmation of basic information about the company (registered office, directors, shareholders) that is required every year on the anniversary of incorporation. Their website will guide you through it. It is nothing to do with the annual accounts.

    5 May 2015

  25. Bobby


    I have a company incorporated and started trading on 02.07.2013, Accounting reference 31.07.2014.

    I submitted the accounts to Companies House on 02.04.2015.

    When would the CT600 be due? and would it need to be 2 CT600?


    5 May 2015

  26. Admin

    You have the following CT600 periods:

    02.07.13 - 01.07.14 due by 01.07.15
    02.07.14 - 31.07.14 due by 31.07.15

    7 May 2015

  27. Ihssan


    My limited company financial year runs from 1/8 to 31/7 , my corporation tax and my self assessment every year done dependent of my profis from between those dates every year . 1 /12/14 i decided to take paid job ( Paye) therefore i asked my accountant to file the company account for cessation he extended my corporation year until 31/12/14 and did the final account . When he calcuated my self assessment for the year 2014/2015 he put 17 months worth of profits ( 31/7/13 to 31/12/14) and added my salaries ( from Dec to April) i ended up with large income ( 18 worth of income ) in one tax year ( 2014/2015) .

    I stopped working as Paye and decided to reactivate the company as DS01 not submitted as yet.

    The accountant told he can not do anything about it as he filed the account .

    Any solution to this problem . I would appreciate your advice and assisstent.

    19 May 2015

  28. Admin

    I probably need more information about the timing of your salary and dividends, but the basic idea is that your salary and dividends which presumably form the majority of the income on your personal tax return are not affected by company accounting periods. Each personal tax return should only have 12 months worth of salary and dividends.

    19 May 2015

  29. Ihssan

    Can i e mail you what my accountant response was as that can give you better idea and if you think there is solution to the problem then i can phone you to discuss more as you cann take over from my current accountant.

    19 May 2015

  30. Admin

    We are not really looking to take on any new clients at the moment, but if you post it here, I will comment on it.

    20 May 2015

  31. Sue

    I am just wondering if anyone can help me wit company account.
    Basically,I need to file corporation tax return(first year account) for the was incorporated on 17 feb 2014.account is prepared till 28 feb 2015.when I tried to process on HMRC website,3 suggested periods popped up
    1. 01-03-2015 till 28-02-2016
    2. 17-03-2015 till 28-02-2015
    3. 17-02-2014 till 16-03-2015
    My understanding is that we have to do 2 seperate return for the first year accounts.first one is for the period 17-02-14 to 16-03-15 and second for the period 17-03-2015 till 38-02-15.according to Hmrc website ,I just need to Complete first accounting period and select no to “accounting service” for the second and just do the computation it true ?if not could you pls guide me.and also how can I split all the figures between two seperate periods if I hve to?and do I hve to split all the figures apart from profit like expenses,depreciation?
    I really appreciate tyour help.
    Thank you.

    20 May 2015

  32. Sue

    Sorry correction*
    First accounting period = 17-02-14 to 16-02-15
    Second accounting period = 17-02-15 to 28-02-15

    20 May 2015

  33. Admin

    I agree with your tax periods:

    First accounting period = 17-02-14 to 16-02-15
    Second accounting period = 17-02-15 to 28-02-15

    Generally, you “attach” the full accounts to the first tax period. For the second, you do not attach accounts, on the basis that they are already submitted.

    You do not split every expense from your accounts. You start with the net profit before tax as one figure, and split that. You then apply adjustments for disallowed expenses (like depreciation) and capital allowances to each tax period separately.

    20 May 2015

  34. Sue

    Thank you for the prompt reply.
    So you meant I should Work out the daily profit.
    Multiply the daily profit by the number of days each return covers.
    Put the relevant profit figures in each tax return.
    Really appreciate thsnk you

    20 May 2015

  35. Admin

    Yes, but before working out the daily profit, you should adjust it for disallowed expenses (like depreciation). You then deduct the capital allowances for each tax period before putting the profit figures in the tax return.

    You might also have different types of income, such as bank interest or rental income, to deal with. If you have, it is getting beyond the scope of what a member of the public should be attempting.

    20 May 2015

  36. Sue

    I am sorry to bother again but one confusion here,

    In your first post you mentioned tht you split profit first then allow adjustments for depreciation but in your later post you mentioned to adjust depreciation before working out daily profit.could you please clarify a bit on this.
    And one final question (I promise :))
    When splitting profit,shall I take 365 days into account or 377 days (365+12 days)

    20 May 2015

  37. Admin

    Sorry for the confusion. You should end up with the same result regardless of the order. We use the first way as it fits better with our tax software, but the HMRC website might work better the second way.

    “When splitting profit,shall I take 365 days into account or 377 days (365+12 days)”

    Definitely 377 days. The fact that you have got a 377-day accounting period is the reason you are having to do all this apportionment to get a 365-day period and then a 12-day period.

    20 May 2015

  38. Henry


    I would appreciate your expert guidance on the following:

    Accounting Reference Date is 31/10/14 (dormant accounts submitted up to 31/10/13).

    Started Trading 13/09/14 (before this company was dormant and HMRC was aware of this).

    Companies House: Accounts for the period 01/11/13 to 31/10/14 (due end of July).

    Corporation Tax Returns = 13/09/14 to 31/10/14.

    Is this correct? Will the deadline be 13/09/15 to submit these?

    Many Thanks

    20 May 2015

  39. Admin

    Correct, except that the deadline for the tax return will be 31/10/15.

    21 May 2015

  40. Rubena

    Hi there,I am in similar situation ,just that mine is over 13 months period.I hve been told either to change the accounting period or do 2 return.if I file 2 seperate return,do I need to apportion turnover and cost of sales figures too?

    21 May 2015

  41. Admin

    I am getting a few questions on this, so I am going to come up with an example computation and include it on this page.

    21 May 2015

  42. Henry

    Or just change the first accounting period to 17/02/14 till 28/02/14,and take it as dormant account,hence everything nil and complete the second return as normal (01/03/14 till 28/02/15)..
    Just that With dormant A/C,select no to “accounting services ” and “computation ” and at the end just choose “dormant account” in the file attachment section.hope this helps

    21 May 2015

  43. Admin

    Of course, the company must actually have been dormant over the period 17/02/14 till 28/02/14.

    21 May 2015

  44. Veddy


    I extended my first accounting reference date at company’s house to 18 months from date of incorporation. do i submit the entire 18 months to company house or do i need to do 2 sets one to cover the 1st 12 months and then the 6 months.

    31 May 2015

  45. Admin

    Companies House will only be looking for one set of accounts, covering the whole period.

    1 June 2015