CH14200 - Record Keeping: How long must records be retained for: Avoidance
Although the law sets out the periods for which a person must retain their records, we can specify a shorter retention period. You will find more detail in CH14800 for direct taxes and CH15300 for VAT.
A shorter retention period must not be specified in any circumstances in which you suspect that avoidance is involved. To do so would be against HMRC’s anti-avoidance strategy.