Long customer terms need a check against GST timing

The customer pays after the expected tax outflow

Imagine a GST-registered business invoices a large job on extended terms. Its forecast includes the eventual customer receipt but assumes there can be no related GST cash requirement until that money arrives.

That assumption needs checking against the business's actual GST accounting method and circumstances. Long payment terms can make the timing difference important even when the job itself is expected to be profitable.

Confirm the method being used

Ask the tax adviser whether the business accounts for GST on a cash or non-cash basis. Do not infer the answer from the format of a management report or a colleague's description of general accounting practices.

Use the method actually applying to the business. Eligibility, changes of method and particular transactions need proper advice rather than an informal switch made to suit a difficult payment period.

Understand the relevant timing distinction

The ATO's small-business education explains that, under non-cash GST accounting, a sale can need to be reported for GST before the customer pays. Its guidance describes the relevant invoice or payment event rather than treating collection as the only trigger.

Have the adviser apply the rules to the transaction. This article does not calculate a BAS liability or establish the treatment of every supply, adjustment or special arrangement.

Source: ATO small business education: Accounting for GST on a non-cash basis

Use the actual expected BAS amount

Place the adviser-supported net tax payment and its applicable date into the forecast. Do not simply add the GST component of one invoice as a separate payment if that would duplicate an amount already included elsewhere.

Other transactions, credits and adjustments can affect the result. Keep the calculation linked to the current tax records rather than using the job invoice alone as the whole-business liability.

Test a later customer receipt

Move the expected customer payment later while keeping the supported tax and operating outgoings visible. Review the funding gap with the accountant and update assumptions when better information becomes available.

Do not assume a delayed customer receipt automatically changes a lodgment or payment obligation. If meeting an obligation is difficult, obtain advice and contact the relevant authority through the appropriate process promptly.

Resolve the assumption before accepting longer terms

For a material job, ask the adviser to confirm the GST timing and forecast treatment before the commercial decision is finalised. Record the answer with the job's other funding assumptions.

The aim is a complete cash timetable. A customer payment date should be assessed alongside the business's actual obligations, rather than being used as a shortcut for deciding when every related outgoing occurs.