Long Accounting period using Taxfiler Accounting Module:

Note – The computations and tax return will show the amounts apportioned on an amounts time basis, but the Capital Allowance figures will still be entered for the accounting period and not the period of accounts. 

Where the accounts are for longer than a 12 month period you will need to submit two CT600 returns, the instructions below give details on how to do this.

Create the accounts for the full period – then if you are using our Accounts Preparation module: 

  • You need to finalise the accounts in the Check & File tab
  • Select Accounts approved – please note that these are fully amendable until submission to Companies House, even after ticking the accounts approved button

The initial 12-month return:

  • Click on Attach button
  • Click on Create tax return button (it will auto-populate the create return box with the dates for the first 12 months of the accounting period)
  • Select ‘Update amounts to tax return’, or click on “Skip” to ignore this process
  • After either updating the return with the figures, or using the “Skip button you will be taken into the tax module,
  • Select ‘Making more than one return now?’ on the company information screen and select ‘Save changes’
  • Click on Trading Profits data input screen you will see that the ‘full accounting period’ is displayed (amounts will be apportioned for the period)
  • Fill in the Capital Allowances and other details as required and complete as far as possible
  • If you have all the information for this return you can now move on to the second return

Creating the Second Return

  • Create a New Tax Return via the Client/case details tab click on the Goto client button
  • Select the Tax Returns tab, then click on +New Tax Return– it will automatically choose the remaining portion of the period
  • Select the create button
  • Check in the Trading Profits data input screen it will automatically detail the period and apportion accordingly.
  • If for whatever reason you do not wish to use the apportioning remove the tick from ‘Apportion amounts to account period’ in the Trading profits section on the Trade Summary tab, click on the Change button
    • You will need to do this for both CT600s, or you can remove the tick before creating the second return – it will still automatically create the second return for the remainder of the period but the amounts won’t be apportioned, instead the full amounts will be displayed in the initial 12 month return only
    • There won’t be any apportionment if the tick has been removed, you can now manually enter the values for the 2 returns as required, via the Adjustments to trade profits data sheets
  • Open the Company information data sheet and tick ‘Making more than one return now?’ and select ‘Not included – submitted with accompanying return’ from the drop-down list as shown below, and click save changes
  • It is important that both returns have the tick ‘Making more than one return now?’ as this allows HMRC to link the submissions and accept the two tax returns for the same accounting period.

To submit the 2 Returns

  • If both returns have been completed, then you can prepare to file by clicking on the Review & File tab for each period in turn and follow the onscreen process for submission.

Long Accounting period manually created:

  • When attaching accounts that have not been prepared from the Taxfiler accounts module you will need to adjust the accounting periods manually
  • From the Tax returns tab, select + New Tax Return button to create a new tax return
  • Create this return for the first 12 months of the period.
  • Select ‘Making more than one return now?’ on the company information screen and select Save changes
  • Select the Data Input tab and select +add a new section
  • A new window opens, select to add ‘trading profits’ data screen, under ‘Period of account’
  • Select Change to enter or amend the date to reflect the ‘long period of accounts’
  • Tick ‘Apportion amounts to account period?’ and click Save changes.


Please note that the computations and tax return will show the amounts apportioned on a time basis, and that the Capital Allowance figures will still be entered for the accounting period and not the period of accounts.

  • Fill in the Capital Allowances and other details as required and complete as far as possible
  • Finish all the details in the 12 months return before going to the next step.
  • Create a New Tax Return by clicking on the Client/case details and Goto client and select Tax Returns tab, and click on + New Tax Return – it will automatically choose the remaining portion of the period
  • Select Trading Profits from the data input screen, the period start and end dates should be for the second shorter period and the profit / (loss) should be apportioned accordingly
  • Open the Company information data sheet and tick ‘Making more than one return now?’  and select ‘Not included – submitted with accompanying return’ from the drop-down list as shown below

Making changes to the Accounts (within Taxfiler) after both tax returns have been created

Make the changes required to the trial balance, and save changes

Select the Check & File tab

Select the Re-attach button

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There is a warning message that a set of accounts is already attached, and that these will be replaced with these accounts, select Confirm Overwrite button if you wish to continue

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Select the button to Update amounts to Tax Return

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The values are updated by Taxfiler to the first return for the 12 month period.

Save the changes and open the second return for the shorter period, open the trading profits tab from the data input screen, where you will need to manually update the Total turnover in the period of account

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You will need to update the Taxable trade profit /(loss) value via the Adjustments to trade profit tab, enter the full amount for the accounting period, and save changes

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Return to the Trade summary tab and you will see that the Profit / (loss) has been apportioned for the shorter period.

Making changes to the tax returns after creating both returns, not using Taxfiler accounting module.

Make the changes in the first 12 month return by selecting the Trade Summary tab from the data input screen and updating the Total turnover in the period of account.

Next select the Adjustments to trade profit tab, update the Net profit/(loss) per the accounts.

Click on the Edit button beside any of the entries that need to be updated, when complete click on Save changes.

Open the second return for the shorter period, repeat the steps above to update any values. Note the values for the full accounting period are entered, Taxfiler will apportion the amounts for the tax return.

Return to the Trade summary tab and you will see that the Profit / (loss) has been apportioned for the shorter period.

Dormant accounts:

When there is a long accounting period where the company is dormant for a portion of the accounting period you will need to follow the process for a long accounting period, and remove the apportionment option (see instructions below), so that you can manually allocate the figures to the correct period.

The system will always create the CT600 return for a 12-month period first, followed by the remaining shorter period.

Where the dormant period is the initial few months (less than a year) edit the accounting periods in the client/case details tab and within the tax return manually enter the values in the adjustments to trade profit tab to force this to be the second return for the non-dormant period.

Make sure that you have unticked the apportionment option tick before creating the second return (see below for instructions)

Click on the + New Tax Return from within the Tax Returns tab and type in the dates for the earlier part of the period, do not include the accounts with this return, but remember to select from the drop-down list on the company information screen within the data input tab ‘Not included – submitted with accompanying return’ or ‘Not included – company dormant’

The dormant period will only be linked by the date for the return and the fact that you have selected “submitting more than 1 return” for both returns on the Company information data sheet within the data input tab.

To remove the Apportionment option

When you remove the option for apportionment in the trading profits section, the link between the two returns will be removed and the costs will need to be entered manually.

To remove the tick select the Trading profits data sheet, under the Trade summary tab, click on the change button 

Untick the apportioned option as below:

You should see the full amount for the period charged to this 12-month portion of the return

The box showing the ‘Profit /(Loss) apportioned to the accounting period’ has been removed.