VCAS6050 - Cash accounting scheme: Leaving the scheme: Withdrawing from the scheme voluntarily
Regulation 60(2) states that:
Subject to regulations 61 and 63 below a person may withdraw from the scheme at the end of any prescribed accounting period.
This allows a business to leave the scheme at the end of a VAT accounting period and return to the normal method of accounting voluntarily if, for example, they find that there is no benefit from operating the scheme or that their accounting system cannot cope with the conditions of the scheme.
The Regulation specifies that a business must leave the scheme at the end of a tax period. It would not be practicable to allow them to change from cash accounting to normal accounting in the middle of a tax period.