VAT on Electricity at Holiday Caravan Parks
First up, is your electricity metered?
Then the park owner will charge you VAT at the standard rate of 20%.
If your supply is individually metered, then HMRC state that the park owner "...may account for VAT on supplies of electricity and gas to caravans at the reduced rate."
The full overview is here: https://www.gov.uk/guidance/vat-treatment-of-caravans-and-houseboats-notice-70120#section3
NACO members can download this guidance and letter templates in the member-only section by logging in here.