7 PAYG Summary Data Errors That Trigger
ATO Reconciliation Mismatches

ATO Consequence: Withholding at 47% (top marginal rate + Medicare levy) instead of the employee's marginal rate if the TFN is missing. If the TFN is present but incorrect — typically two digits transposed — the employee's myGov pre-fill shows an employer they do not recognise, the employee disputes the income statement, and the ATO issues a data-matching query to the employer. Resolution: 30 minutes to two hours per affected employee.

How It Happens: The payroll officer types the TFN from the payment summary into the reconciliation spreadsheet and transposes two digits — 123 456 789 becomes 123 456 798. All nine digits are present, so a visual scan does not catch the error. The spreadsheet is used to verify STP data, and the incorrect TFN makes it into the finalisation. For paper summaries from third-party providers, the TFN may be handwritten and difficult to read — an '8' that looks like a '3' under poor scan quality becomes a three-hour investigation.

Prevention During Extraction: Automated extraction reads the TFN from the document's visual content — no human typing, no transposition. For batch processing, a Computed Column that runs the ATO's TFN checksum algorithm (weighted sum of first eight digits modulo 11 must equal the ninth digit) on every extracted TFN flags invalid numbers before the spreadsheet opens. An additional column that flags duplicate TFNs across rows catches the scenario where two employees share the same incorrectly entered TFN — a pattern that would otherwise survive both extraction and visual review.

ATO Consequence: If RFBA is omitted from the summary but the employee actually received reportable fringe benefits, the employee's income for Medicare levy surcharge and HELP repayment purposes is understated. The employee may receive a tax refund they are not entitled to, or avoid a levy they should have paid. When the ATO cross-references the employer's FBT return (lodged by 21 May for the FBT year ending 31 March) against the RFBA amounts reported on PAYG summaries, a discrepancy triggers an employer-level review — not just a single-employee query. An incorrect RFBA on one summary can cascade into a compliance review of the employer's entire FBT reporting.

How It Happens: The FBT year (1 April to 31 March) and the financial year (1 July to 30 June) do not align. A fringe benefit provided in April 2026 belongs to the 2026-27 FBT year but may appear on an employee's 2025-26 PAYG summary if the payroll team incorrectly applies financial-year logic to the RFBA field. Alternatively, the RFBA figure was correctly calculated for the FBT return but never updated in the payroll system — the summary shows $0 RFBA, but the FBT return reports a non-zero grossed-up value for that employee, and the ATO's automated cross-reference flags the inconsistency.

Prevention During Extraction: A Computed Column that checks: if an employee's total remuneration (Gross Payments + any salary sacrifice) exceeds $100,000 and RFBA = $0, flag for review — high-income employees are statistically more likely to receive reportable fringe benefits. A separate validation rule: for any employee with a known fringe benefit arrangement (company car, health insurance, entertainment benefits), confirm RFBA is non-zero and matches the FBT return schedule. The extraction spreadsheet, cross-referenced against the FBT return before the 14 July finalisation, catches RFBA mismatches while there is still time to correct the summary.

ATO Consequence: Misclassifying a lump sum payment changes the employee's assessable income and tax liability. Entering a $15,000 genuine redundancy payment as Lump Sum A (taxable unused annual leave) instead of Lump Sum D (tax-free redundancy component) means the employee's income statement shows $15,000 of additional assessable income. The employee faces tax on that amount — potentially $4,875 at the 32.5% marginal rate plus Medicare levy — disputes the assessment, and lodges a complaint. The employer must reissue the summary, submit an amended STP report, and potentially compensate the employee for any penalty interest the ATO charged on the incorrect assessment. Worse: a liquidator or administrator reviewing a business that has been misclassifying lump sum payments across multiple employees for multiple years may identify a systemic payroll compliance failure — a far more serious finding than a single misclassified payment.

How It Happens: The payroll software's termination payment workflow asks the payroll officer to select a lump sum type from a dropdown. The officer, unfamiliar with the tax distinction between Type A (annual leave — taxable) and Type D (redundancy — tax-free), selects the wrong option. The software generates the summary with the incorrect classification, and no subsequent review catches it because the dollar amount — $15,000 — appears plausible regardless of the type. The error only surfaces when the employee's tax return is assessed and the ATO's system detects that a lump sum D was reported by the employer but the employee's return shows taxable income that includes the amount — or vice versa.

Prevention During Extraction: Create a validation rule during extraction: for any employee with a non-zero Lump Sum D, flag the row for verification of a genuine redundancy or early retirement scheme — and require documentation (redundancy letter, early retirement scheme approval) before the summary is issued. For any employee with a non-zero Lump Sum A or B, confirm that the employee actually terminated during the financial year — a current employee should not have unused leave lump sums. A Computed Column that cross-references leave balances from the payroll system against the lump sum amounts on the summary catches discrepancies where the leave payout figure on the summary does not match the accrued leave balance at termination.

ATO Consequence: For employees reported through STP, the STP finalisation declaration and the PAYG payment summary (if both exist for the same employee for the same period — which they should not, but sometimes do) must report identical figures. A mismatch means the employee receives two different versions of their income from the same employer: one through myGov (STP) and one on the paper/PDF summary. The employee's tax return — which uses the myGov pre-fill — may not match the payment summary they hold. The ATO's data-matching detects the inconsistency and queries both the employer and the employee. Resolution: the employer must determine which figure is correct, correct the incorrect one (STP update event or reissued summary), and notify the employee.

How It Happens: The most common scenario: an employee transitioned from a pre-STP period to an STP period within the same financial year (e.g., the employer implemented STP in October 2025). The payroll system generates a PAYG payment summary for the July-September pre-STP period and STP data for the October-June period. If the two datasets are not reconciled before finalisation, the employee may appear in both reports with overlapping or inconsistent figures. A less common but equally problematic scenario: a manual pay adjustment entered after STP finalisation updates the payroll system but the corresponding STP update event is not submitted — the STP data the ATO holds is now out of date, but no discrepancy flag is visible within the employer's own systems.

Prevention During Extraction: For any employee who received both a traditional PAYG summary (pre-STP period) and STP-reported data (post-transition period) within the same financial year, extract both data sources into the reconciliation spreadsheet and reconcile the combined totals against the payroll system's full-year report. The extraction spreadsheet becomes the single source of truth: VLOOKUP each employee's TFN against the STP data and the pre-STP summary, confirm the sum of gross payments and tax withheld across both sources equals the payroll year-to-date report, and flag any employee whose combined figure does not match. This prevents the scenario where the STP data and the summary both look internally consistent but report different totals for the same employee.

ATO Consequence: Allowances must be separately itemised on the PAYG payment summary because different allowance types have different tax treatments. A tool allowance may be tax-free up to a specified ATO rate; a travel allowance may be partly taxable depending on whether a travel diary was maintained; a first aid allowance is fully taxable. If an allowance is lumped into Gross Payments without separate itemisation, the employee cannot claim the correct tax treatment on their return. If the allowance is omitted entirely from the summary, the employee's reported income is understated — and the ATO's data-matching (which compares the employer's BAS wage totals against the sum of employee summary figures) detects the gap. An allowance discrepancy typically surfaces as a BAS-to-summaries mismatch — the wages reported on BAS are higher than the sum of gross payments on summaries, triggering an ATO query about unreported employee income.

How It Happens: The payroll system may code allowances as part of gross wages for internal reporting purposes but print them as a separate line on the PAYG summary. If the payroll officer extracting the summary types the gross payment figure as it appears in the payroll register — which may include allowances — but the summary prints allowances separately, the extracted figure is too high. Conversely, if the payroll officer types the allowance amounts from the summary but forgets to include them in the gross payment total, the extracted figure is too low. The error is a mismatch between what the payroll system reports internally and what the summary reports externally — and the extraction spreadsheet that trusts one source without verifying against the other propagates the error.

Prevention During Extraction: Extract allowances as separate columns in the output schema. A Computed Column that sums Gross Payments plus all allowance columns and compares the result against the payroll system's year-to-date gross earnings report catches the case where allowances were included in gross in one source but separated in another. A separate validation column that flags any non-zero allowance type where the amount appears implausible — a $50,000 tool allowance for an office worker, or a $200 travel allowance for a field technician who travelled 5,000 km during the year — catches misclassification without requiring line-by-line review.

ATO Consequence: An Employment Termination Payment (ETP) is assigned an ETP code that determines its tax treatment: R for genuine redundancy, O for other (resignation, dismissal, golden handshake), D for death benefit, B for invalidity, N for non-excluded payments. The ETP cap — the maximum amount that receives concessional tax treatment — depends on the code. A payment coded as O (other) when it should be R (redundancy) means the employee receives a lower ETP cap: $245,000 for 2025-26 (indexed annually) for code R, but potentially only the whole-of-income cap of $180,000 minus other taxable income for code O — a difference of tens of thousands of dollars in taxable vs concessionally taxed income. The employee discovers the error when their tax return shows a much larger tax liability on the ETP than expected. The employer must reissue the ETP payment summary with the correct code, recalculate the tax withheld, and potentially compensate the employee for any additional tax and interest.

How It Happens: The payroll officer processing the termination in the payroll software is presented with a dropdown of ETP codes — R, O, D, B, N — with minimal on-screen explanation of what each code means for tax purposes. The officer selects the code that "sounds right" rather than the code that matches the termination reason. For a redundancy where the employee signed a deed of release (which may use language like "ex gratia payment" or "termination payment" without specifying "redundancy"), the officer may select O (other) because the deed does not use the word "redundancy" — even though the termination meets the ATO's definition of genuine redundancy. The code is stored in the payroll system, printed on the ETP summary, and reported to the ATO through STP — and no subsequent review catches the misclassification because the total ETP amount is correct regardless of the code.

Prevention During Extraction: Extract the ETP code as a separate column and cross-reference it against the termination reason recorded in the HR system. A Computed Column that flags any ETP with code O where the termination reason is "redundancy" or "retrenchment" — or code R where the termination reason is "resignation" — surfaces potential misclassifications before the summary reaches the employee. For batch extraction of multiple ETP summaries, a column that groups ETP amounts by code and compares the distribution against expected patterns (a company going through a single redundancy round should not have a mix of R and O codes for employees terminated in the same process) catches systemic coding errors.

ATO Consequence: The number of employees for whom PAYG summaries are issued must match the number of employees for whom PAYG withholding was reported to the ATO — through STP, BAS, and the annual report. An employee who was paid during the year but did not receive a summary has no record of their income and tax withheld, cannot complete their tax return accurately, and — when they eventually receive a summary or discover the omission — may already have lodged an incorrect return. The ATO's data-matching flags the gap: the total number of employees with PAYG withholding on the annual report is fewer than the number of employees on the BAS, or the total gross payments on the summaries is less than the wages reported on BAS. The employer must explain the discrepancy and, if employees were missed, issue retrospective summaries — potentially for a tax year that has already closed.

How It Happens: Employees who left during the financial year but worked for part of it are the most commonly omitted group. The payroll officer generates summaries from the current employee list — which excludes terminated employees — and does not cross-check against the full-year payroll register. Casual employees who worked a single shift and had $12 in tax withheld are another common omission: the payroll team may assume a threshold below which summaries are not required, but the ATO requires a summary for every worker who had tax withheld, regardless of the amount. Contractors under a voluntary withholding agreement who received a separate NAT 72545 summary (business and personal services income) may be omitted from the annual report if the payroll team thinks only NAT 0046 summaries count.

Prevention During Extraction: Before finalising, extract every PAYG summary — including ETP summaries, business and personal services income summaries, and summaries for terminated and casual employees — into a single spreadsheet. Add a Computed Column that counts unique TFNs in the extraction and displays the total number of employees. Compare this count against: (a) the number of employees on the payroll system's year-to-date report who had PAYG withholding (not just the current active employee list), (b) the number of employees reported on the four quarterly BAS, and (c) the number of employees with STP data finalised. Any difference between these counts — even a difference of one — requires investigation before the annual report is lodged. A single missing summary is an ATO query waiting to happen.