VATLP22500 - Option to tax: permission options
If a person has made, or intends to make, exempt supplies of the relevant land or buildings within the 10 years prior to the date they wish their option to take effect, they will need HMRC’s written permission in order to opt to tax unless one of the ‘automatic permission conditions’ is met.
The ‘automatic permission conditions’ and general guidance on permission options can be found in section 5 of Notice 742A.