Casino duty is the primary tax levied on casino gaming revenue under the Gambling Act 2003. The duty is calculated as a percentage of "gaming machine profit" (GMP) for electronic gaming machines and "casino win" for table games — essentially the gross gaming revenue after prizes are paid out but before operating expenses.

The standard casino duty rate is 4% of gross gaming revenue for table games. For electronic gaming machines within casinos, the duty rate aligns with Class 4 gaming machine duties, which vary based on revenue thresholds. This tiered structure means larger casinos typically pay higher effective duty rates on their pokies revenue.

Casino duty is paid to the Department of Internal Affairs and deposited into the government's Consolidated Fund. Unlike Class 4 gaming machine operators (pubs and clubs), casinos are not required to distribute profits to community purposes, though some operators maintain voluntary community funding programmes.

All casino operators must pay a Problem Gambling Levy to fund prevention, intervention, and treatment services for problem gambling. The levy is set by the Ministry of Health and reviewed regularly based on the costs of providing problem gambling services nationwide.

The levy rate is calculated as a percentage of gross gaming revenue, with rates varying by gambling sector. For casinos, the levy is typically lower than for Class 4 gaming machines (pokies in pubs and clubs) due to different harm profiles and revenue scales. Recent levy rates for casinos have been approximately 1.12% of gross gaming revenue.

Levy funds support problem gambling services including the 24/7 Gambling Helpline (0800 654 655), face-to-face counselling through the Problem Gambling Foundation, public awareness campaigns, research into gambling harm, and training for health professionals. The levy ensures the industry contributes directly to minimising the harm it may cause.

Casino operators are subject to Goods and Services Tax (GST) at the standard 15% rate on most revenue streams. However, GST treatment of gambling revenue has specific rules — GST is calculated on the "margin" (gross gaming revenue minus prizes paid) rather than total turnover, reflecting that prize payouts are not consideration for a supply.

Additionally, casinos pay corporate income tax at the standard New Zealand company tax rate of 28% on their taxable profits. This is calculated on net profit after deducting operating expenses, including gaming duty and the problem gambling levy, but gaming revenue itself is not exempt from income tax calculations.

Compliance and reporting requirements are extensive. Casinos must maintain detailed financial records, submit regular GST returns, file annual income tax returns, and provide the DIA with quarterly gaming duty calculations and payments. Failure to meet tax obligations can result in penalties, interest charges, and potential licence sanctions.

New Zealand's casino tax rates are relatively moderate compared to some international jurisdictions. For example, Australian states charge casino duties ranging from 10-30% depending on the state and game type, while some European countries impose duties exceeding 40% of gross gaming revenue.

The New Zealand approach reflects a balance between revenue generation and industry sustainability. Lower duty rates encourage compliance and legitimate operation while still generating substantial government revenue. In the 2022/23 financial year, casinos contributed over $100 million in gaming duties and levies combined.

Unlike some jurisdictions, New Zealand does not impose separate licence fees or annual charges beyond the gaming duty and levy structure. This simplified taxation framework reduces administrative burden while ensuring operators contribute fairly based on their gaming revenue and the potential harm their operations may cause.