Checklist · 3 min read

The client document checklist for a GST return

Published 13 October 2026 · AIGOCO Accounting

Most of the work of a GST return happens before you start it: getting the right documents from the client. This checklist covers what to ask for each period, depending on how the client's business is set up.

The checklist

1. 1Bank statements for every accountEach business account, every month of the period, including credit cards and savings accounts the business uses.
2. 2Sales invoices or a sales summaryEverything invoiced in the period, or a report from the client's accounting or point-of-sale system.
3. 3Purchase receipts and supplier invoicesTaxable supply information for every purchase they want to claim GST on.
4. 4Cash and EFTPOS takingsFor clients who take cash or card payments: a summary of takings for the period.
5. 5Vehicle logbook and fuel receiptsFor clients who claim a business share of vehicle costs.
6. 6Payroll summariesFor clients with employees, so wages and PAYE line up with the bank.
7. 7Answers to your questionsAnything unusual in the bank: a large payment, a transfer between accounts, a new asset.

Ask once, with only what's missing

Clients respond faster to one short list than to a long generic one. Send each client only the items that apply to their business and haven't arrived yet, and remind them about those, not everything.

When to ask

Ask for each month's bank statement a working day after the month ends, then remind clients two weeks and one week before the GST due date. Our GST due dates guide lists every date.

This guide is general information, not tax advice. Check IRD's website or your own records for each client's situation.