Relevant IRD publications:

The GST guide
The GST guide provides information and guidance for preparation of Goods and Services Tax returns in New Zealand.

The Tool for business
The Tool for business helps you get all your small business tax issues sorted quickly and simply.

Becoming an employer
When you start employing staff, you must register with us as an employer. You must also decide whether your staff are employees or self-employed contractors as the tax treatment for each is different.

Employing staff
There are things you must do or check when a staff member starts or stops working for you, when your business changes or ceases or if you want to employ your spouse or any foreign workers.

Payroll
Employers must deduct PAYE, including tax on schedular payments (formerly withholding payments) from payments made to staff or contractors. Deductions may also be needed for student loan repayments, child support, Kiwisaver, or any benefits, bonuses or other allowances that you pay.

Keeping records
This section has information about which records of your PAYE deductions you need to keep, and for how long.