GST in Coffer

GST is 15% on most goods and services in New Zealand. If you're GST-registered, every invoice you raise adds 15% on top of your ex-GST price, and that 15% belongs to IRD, not to you. Coffer's job is to keep that mental separation visible in real numbers, end to end, from the moment you issue the invoice to the moment you file the return.

When you need to register

You must register for GST once your turnover passes $60,000 in any rolling 12-month period. Rolling, not financial year: if you cross the threshold in June 2026, the clock has been running for the previous 12 months, not from 1 April.

Once registered, you stay registered until you deregister with IRD (usually because your turnover has dropped back below threshold for an extended period, or you've stopped trading). You can also register voluntarily before crossing $60,000, which makes sense if most of your work is for GST-registered clients who can claim back the GST you charge them.

The 15% mechanic, on an actual invoice

Say you do a $5,000 piece of work for a client. With GST registered:

• Ex-GST amount: $5,000.00 (this is what you actually earn for the work)
• GST (15%): $750.00 (this belongs to IRD)
• Invoice total: $5,750.00 (what the client pays)

When the invoice is created in Coffer, you enter the ex-GST amount and Coffer calculates the 15% and the total automatically. The PDF that goes to the client shows all three lines plus your GST number, which is what IRD requires for a valid tax invoice.

What happens when the client pays

Coffer doesn't move money. What changes when you mark an invoice paid is the dashboard math:

• Your ringfenced GST goes up by $750. That number is the running total of GST you owe IRD across every paid-but-not-yet-returned invoice.
• Your ringfenced income tax goes up by $1,685 (33.7% of $5,000 by default, or the bracket-aware amount if you've set that up).
• Your available to spend goes up by $2,565 (the $5,750 you actually received, minus the two ringfences).

The same applies in reverse: if you delete a paid invoice or flip it back to pending, the ringfences shrink to match. The dashboard always reflects the current state of paid revenue, nothing more.

Filing a GST return

When a return is due, start with the GST return summary (Tax events → GST return summary). Pick the filing period and Coffer lays out the figures in the order the return asks for them: total sales and income for the period (counted when paid), zero-rated supplies split out, GST collected, your purchases with claimable GST and the credit, and the net GST to pay or refund. It's printable and downloads as a spreadsheet file, so it works as your filing crib sheet or as a hand-off to your accountant. One note when copying into myIR: myIR calculates the GST from the sales figure you type, so a few cents' difference from Coffer's collected figure is normal rounding - go with myIR's.

After you file and pay, log the payment in Coffer under Tax events as a GST return with the amount paid and a period label (e.g. “GST Aug-Sep 2026”). The summary for that period then shows the payment against the figures, so past periods stay reconciled.

Logging the return reduces your ringfenced GST by the amount paid. If you filed exactly what Coffer had ringfenced, your GST ringfence drops to zero for that period and starts accruing again on the next paid invoice. If you paid more or less than the ringfenced amount (rare, but happens when claiming GST back on business expenses you haven't recorded in Coffer), the difference shows in the ringfence as a positive or negative balance.

Due dates and reminders

Your GST return is generally due on the 28th of the month following the end of the period. For two-monthly filers with an Aug-Sep period, that's 28 October. The Dashboard shows the next GST due date with a countdown so you can plan for it, and the Tax events page lists every past and upcoming filing with what was paid each time.

Coffer pre-fills the standard schedule based on the GST filing frequency you set in Settings (monthly, two-monthly, or six-monthly). If you have a special balance date or your accountant uses a non-standard cadence, you can fine-tune individual due dates from Settings.

Overseas clients and zero-rated work

Services exported to a non-resident client are typically zero-rated for GST: you charge them no GST, but you can still claim back any GST on your business expenses related to that work. Strictly, “zero-rated” is a GST rate of 0% (not the same as “exempt”), and the invoice still has to say so explicitly.

Coffer's invoice form doesn't have a dedicated zero-rated toggle today. The simplest workaround is to enter the invoice ex-GST as $0 GST and note in the description that the supply is zero-rated under section 11A of the GST Act. For more than the occasional zero-rated invoice, talk to your accountant about the cleanest record-keeping approach for your situation.