This is your real scenario or home work?
Please tell me what I have asked before, thanks.
I cannot telephone you, please let me know that do you have made any claims to HMRC for tax credits and because of that they want to examine your record?
Please see the information below which I have gathered for you and if you need details so links are also provided so you can analyse your case. Links for Assesing Time Limit tabe are also provided.
Reopening Earlier Years: Discovery in SA Years: SA Time Limits
The normal and extended assessment time limits changed on 1 April 2010. The guidance below applies to assessments made before that date. For guidance on the time limits that apply to all assessments made on or after 1 April 2010 see CH53000+.
Normal Time Limits
Where there was incomplete disclosure without fraudulent or negligent conduct, the time limit for making a discovery assessment on an individual was five years from 31 January next following the tax year to which it relates.
Thus the time limit for an individual for 1996/97 was 31 January 2003.
The time limit for recovery of an overpayment was the later of
Extended Time Limits
Where there was fraudulent or negligent conduct the time limit for making a discovery assessment was extended for an individual to 20 years from 31 January next following the tax year to which it relates. See EM3340+ for operational procedures.
Reference Link :- https://www.gov.uk/hmrc-internal-manuals/enquiry-manual/em3270
Link for the Time table (income tax and Capital gain) :- https://www.gov.uk/hmrc-internal-manuals/compliance-handbook/ch56100
For VAT:- https://www.gov.uk/hmrc-internal-manuals/compliance-handbook/ch56300
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