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HMRC internal manual

Enquiry Manual

Opening the Enquiry: Statute: ITSA Time Limits


TMA 70/S12AC(2)

Returns made on or before usual filing date

Until 31 March 2008 the time limit for opening enquiries on returns received on or before the fixed 31 January filing date was the following 31 January.

[Before FA2001 the time limit for opening such enquiries was 30 January.]

From 1 April 2008 when a tax return is received on or before the relevant filing deadline, the enquiry window will run for a full 12 months from the date the tax return is received. So for a return received by HMRC on 20 June 2008, the enquiry window will run to 20 June 2009.

Late Returns

If a return is delivered after the fixed filing date, the enquiry period is extended. The enquiry window will in these cases not close until the quarter day next following the first anniversary of the day on which the return was made.


A taxpayer can make an amendment up to 12 months from the filing date.

The amendment does not change the enquiry period for the return, which is explained above.

There is however a separate enquiry window for the amendment. The enquiry period for the amendment is up to the quarter day next, following the first anniversary of the date that the amendment was made.

The quarter days are 31 January, 30 April, 31 July and 31 October.

Receipt of Notice

Your notice must be received before the time limit. The Courts assume that second class post takes 4 working days to be delivered and first class post takes 2 working days. Working days do not include Saturdays, Sundays or Bank Holidays.

If you have no alternative other than issuing an enquiry notice close to the deadline, you may need to demonstrate to a Reviewing Officer or a Tribunal that the notice entered the postal system in sufficient time for it to be delivered before the time limit.

Where a notice is issued within 7 working days of the deadline it should be sent first class and preferably using ‘track and trace’ or another method of postal delivery that will help you to demonstrate when it was delivered.

Alternatively, where this is not possible, you will need to make a clear record in both Caseflow and any paper file of the fact that the letter was posted first class and the date of posting.

If you need written authorisation from your manager for the use of first class post, a copy of the authority should be uploaded to Caseflow and/or also placed in the file as evidence.

All notices relating to Income Tax, Capital Gains Tax or Corporation Tax enquiries must be in writing, see EM0067.