TasHoliday1
No mention of requring a booking or membership of any kind. Does require booking.
Interislander Travel
Get 15% off your Interislander fare when you book to stay at any of our New Zealand Tasman Holiday Parks. Book your travel between the North and South Island on the Interislander and use our code ‘TasHoliday1’ and you will receive 15% off. This promo code can be entered when you input your payment details and the fee will automatically be discounted.For more information or to book your Interislander travels, please visit www.interislander.co.nz
T&C’s:
This discount code is only valid on bookings made directly via the Interislander website. This code is not eligible on bookings made through third party websites.
No refunds will be given for unclaimed discounts issued.
This discount cannot be exchanged for cash.
Looks like there are further terms when you enter the code at checkout, including needing a booking confirmation for Tasman Holiday Park:
“15% discount off Rate of the Day on Passenger & Vehicles. Valid for travel through to 30th June 2024 inclusive. Discount amount has no refund value & conditions of the fare purchased apply. Not available in conjunction with any other offer. Confirmation of a booking at a Tasman Holiday Park needs to be produced at check in.”