How to cancel your VAT registration?
You can cancel your VAT Registration by completing Change of Registration Details or Cancellation of Registration Form and returning it to IRD. Cancellation shall take effect from the last calendar day of the tax period during which any such taxable activity ceased or from such date as the Comptroller may determine.
Until your registration is cancelled, you'll have to continue collecting and accounting for VAT. IRD may refuse your request for voluntary deregistration, in which case you'll have to continue collecting and accounting for VAT.
If your registration is cancelled, you are obligated to pay tax and file returns and fulfill any obligations you were required to uphold during the time you were registered and until cancellation takes effect.