Currency: The New Zealand dollar (NZD) is the official currency. The economy is largely cash-based, so bring enough NZD with you from New Zealand. Kiwibank in Alofi handles cash withdrawals via Visa, Mastercard, or NZ EFTPOS (fees apply). Some accommodation and tour operators accept credit cards, but don't rely on it.
Language: Niuean and English are both official languages. English is widely spoken.
Electricity: New Zealand standard (230V, Type I plug). No adaptor needed if you're coming from Australia or New Zealand.
Health: Niue has a hospital in Alofi with basic services. Serious medical cases are evacuated to New Zealand. Travel insurance with evacuation cover is strongly recommended.
Communications: Mobile coverage is limited to parts of the island near Alofi. Wi-Fi is available at some accommodation and in Alofi. Don't count on being connected everywhere.
Shopping: There is a small market in Alofi on Tuesday, Wednesday, and Friday mornings, next to the Niue Tourism Visitor Information Centre. It's the best place to buy local produce and sometimes coconut crab. A handful of shops in Alofi sell basic supplies.
Sunday: Niue is a strongly Christian society. Most businesses are closed on Sundays, including many restaurants. Plan accordingly.
Departure: There is no departure tax collected at the airport — it is included in the airfare.