First 13,500 users. Expires 30 August 2020, 11:55pm NZST.
Blurb from T&Cs:
Unlimited until 30 Aug
$20 minimum order
Delivery orders only
At selected restaurants
This offer is for free delivery on your order from McDonald's® NZ via the Uber Eats app (Offer). An amount equivalent to the delivery fee will be deducted from your total order value as a 'promotion'. To redeem this Offer, open the Uber Eats app, apply the promo code MACCAS2YOU to your account, search for a participating McDonald's, add 1 or more items to your cart to the minimum value $20 (excluding delivery fee), place your order and then track your order via the Uber Eats app. Limited to the first 13,500 users who apply the promo code on the Uber Eats app. You may redeem this Offer for multiple orders. You must apply the promo code before you redeem this Offer. This Offer is not valid in conjunction with any other offer. Valid in New Zealand where Uber Eats is available only at participating restaurants in select locations during operation hours. Delivery prices and operating hours may vary. Offer expires at 11:55pm NZST on Sunday 30th August 2020. McDonald's reserves it's rights to amend the terms of the promotion, including applicable dates, in its sole discretion at any time.
Some more codes worth trying (targeted - but for any store)
3 free deliveries: eats4949
2 free deliveries: eats2041 - this one's probably more likely to work as a lot of my accounts got emailed this one