8. GST and tax rates

8.1 Tax rates

A tax rate describes how a supply is treated for GST: Standard (taxable), Zero-rated or Exempt. Each rate has a name, a percentage, an active flag and, for one rate, the default flag.

Open Accounting → Tax rates.
Select Add tax rate.
Enter a name (for example “GST 15%”), the rate and the treatment.
Mark the rate as default if it should be preselected on new lines. Only one active rate is the default.
Deactivate a rate to remove it from new documents; historical lines keep the rate they were posted with.

Figure 8.1 — Tax rates with their GST treatment and default flag.

8.2 GST configuration

GST registration and filing frequency are organisation settings:

Registered for GST — when off, the organisation charges and claims no GST.
GST filing frequency — monthly, two-monthly (the New Zealand default) or six-monthly.
Accounting basis — accrual or cash, which determines when GST is recognised.

Set these in Organisation → Settings before preparing the first return.

8.3 The GST return register

Accounting → GST returns lists every prepared return with its period, due date, status, GST to pay or refund, and filing details.

A Draft return can be recalculated, adjusted, deleted or marked filed.
A Filed return is frozen with its filing trail and can only be reopened.
Each taxable period may only have one return, so a period cannot be filed twice.

8.4 Prepare a GST101 return

Open Accounting → GST returns and select Prepare GST return.
Choose a period from the period picker, or enter a custom start and end date. The due date and return number are derived from the period end.
Review the GST101 boxes. They are calculated from posted invoices, credit notes and supplier bills, classified by each line's tax treatment:

Box	Meaning
5	Total sales and income, including GST and zero-rated supplies
6	Zero-rated supplies included in Box 5
7	Taxable supplies (Box 5 less Box 6)
8	GST collected on sales and income (output GST)
9	Debit adjustments (entered by you)
10	Total GST collected (Box 8 plus Box 9)
11	Total purchases and expenses, including GST
12	GST credit on purchases and expenses (input GST)
13	Credit adjustments (entered by you)
14	Total GST credit (Box 12 plus Box 13)
15	GST to pay or refund (Box 10 less Box 14)

If needed, enter Box 9 and Box 13 adjustments and a reason. The two adjustment boxes are the only figures you can type; every other box is calculated from the documents.
Check the Supply breakdown and the Transactions in the period panels: they list the documents behind the totals, grouped by tax rate and treatment.
Check Reconciliation with the ledger: it compares the GST control account movement with Box 15 and shows the variance.
Select Prepare draft return.

Figure 8.4 — Preparing a GST101, part 1: the period and the sales boxes (5–10).

Figure 8.5 — Preparing a GST101, part 2: the purchase and GST boxes, adjustments, ledger reconciliation, supply breakdown and transactions.

8.5 Adjust, file and export a return

On a draft return:

Recalculate re-runs the calculation after late postings, keeping your adjustment boxes and note.
Save adjustments updates Box 9, Box 13 and the reason.
Mark filed records the filing, the IRD receipt number (optional) and the filing date, and freezes the return.
Reopen moves a filed return back to draft for correction.
Delete removes a draft; a filed return is never deleted.
Export produces the return as Excel or PDF.

A positive Box 15 is GST to pay; a negative amount is a refund. A variance in the ledger reconciliation is a prompt to check unposted documents, journals that touch the GST account, or adjustments.