What Are STP Adjust Events & How Can I Use Them to Correct BAS Pre-Fill Amounts?

This FAQ explains how STP Phase 2 affects W1 and W2 pre-filling on your BAS, and when you might use an Adjust event in Lightning Payroll.

Accurate Year-to-Date (YTD) Reporting Is What Matters Most

Every New and Update STP submission carries the correct year-to-date (YTD) figures for each employee. These YTD totals feed the employee's Income Statement and are the part of STP the ATO relies on most.

What W1 and W2 Are

W1 is the total gross payments you have made to workers for the BAS period. W2 is the total tax withheld from those payments. Under STP Phase 2 the ATO uses the gross and tax components of your New and Adjust events to pre-fill W1 and W2 on your activity statement.

Pre-fill is only a convenience. You can and should overwrite it with the figures from your own payroll reports if they differ. To confirm your real BAS totals, run a Group Tax or Pay Summary report in Lightning Payroll for the period and enter those W1 and W2 values when you lodge. The figures you lodge are what matter for PAYG, not the pre-fill.

The Three STP Event Types

• New — sends full YTD data for all employees in the pay run, plus employer-level W1 and W2 for that pay date range.
• Update — sends updated YTD data only; it does not affect employer W1 or W2.
• Adjust — sends only the difference to add to or subtract from previously lodged W1 and W2 totals for the period. Employee YTD data stays unchanged.

Because BAS relies on the totals you actually lodge, Adjust events are largely for tidy record-keeping. Your BAS will be correct as long as you key in the right W1 and W2 figures, even if you never lodge an Adjust.

For more detail on the event types, see our FAQ on New, Adjust and Update events.

When To Use an Adjust Event

Avoid an Adjust event unless you are certain the ATO's pre-fill is out by a known amount and you want it cleared for peace of mind. An Adjust is optional and is not required to lodge a correct BAS or PAYG.

Reconciling Your Totals With the ATO

1. Generate a Group Tax report using the processed date filter and note the W1 and W2 totals.
2. Open Pays >> Single Touch >> Single Touch Mailbox and filter to the same dates.
3. Compare the totals shown beneath the mailbox table (these include New and prior Adjust events only).

Calculating and Lodging an Adjust Event

If the totals differ:

1. Subtract the mailbox W1 and W2 from your report W1 and W2. For example, a W1 difference of $56,773.39 - $54,465.70 = $2,307.69, and a W2 difference of $14,427.00 - $13,813.00 = $614.00.
2. Go to Pays >> Single Touch >> Submit Payroll To ATO and choose Adjust incorrect pay/new event parent totals.
3. Enter positive values to increase W1 or W2, or negative values (for example -500.00) to reduce them.

After You Lodge

Allow up to 72 hours for the adjustment to appear in Online Services for Business and to refresh any BAS pre-fill, although it usually updates straight away.

The figures you type on your BAS are final for PAYG. Your accurate employee YTD data is already handled by your regular New or Update events, so there is no need to worry if an Adjust event feels unnecessary. Lodge the right W1 and W2 and you are compliant.