How to join
You must be eligible to join the scheme. You join at the beginning of a VAT accounting period.
You do not have to tell HM Revenue and Customs (HMRC) you use cash accounting.
How to leave
You can leave the scheme at any time, but you must leave if you’re no longer eligible to use it. You should leave at the end of a VAT accounting period.
You do not have to tell HMRC you’ve stopped using it, but you must report and pay HMRC any outstanding VAT (whether your customers have paid you or not).
You can report and pay the outstanding VAT over 6 months.
If your VAT taxable turnover exceeded £1.35 million in the last 3 months you must report and pay straight away.
You must pay immediately if HMRC has written to you to withdraw your use of the scheme.