Free Calculator · Updated 18 May 2026
Model ATO FTL penalty units by entity size and days late, layer on daily-compounding General Interest Charge, and check the remission outlook before drafting a PS LA 2011/19 submission.
Indicative estimate
Output is directional — verify against PS LA 2011/19 and the current penalty unit rate at ato.gov.au before relying on figures for client advice or remission submissions.
BAS note: Self-lodge Q1 due 28 Oct · Q2 28 Feb · Q3 28 Apr · Q4 28 Jul
Current rate $330 (from 7 Nov 2024). Editable for past or forecast periods.
Counted from the day after the due date. 1 unit per 28 days (or part), capped at 5 units.
Outstanding principal on which GIC accrues daily.
ATO publishes a quarterly GIC rate. Default reflects the current quarter — adjust for the period your shortfall sat outstanding.
How To Use
Step 1
Use aggregated turnover (current or prior year). Small <$1m = 1×, Medium $1m–$20m = 2×, Large >$20m = 5×. Significant global entities can trigger higher base amounts — handle separately.
Step 2
Use the agent program date if the client is on your register by 31 October — not the self-lodger date. Days are inclusive of weekends and public holidays.
Step 3
Penalty unit: $330 from 7 Nov 2024. GIC: refresh each quarter from ato.gov.au — the rate moves with the 90-day Bank Accepted Bill rate plus an uplift.
Step 4
Lodge the outstanding form before submitting your remission request — unresolved forms reduce the likelihood of a favourable outcome and let GIC keep compounding.
Practitioner Notes
PS LA 2011/19 lists serious illness, natural disaster, family bereavement, agent error, and system outages as primary grounds. First-offence + prompt rectification is commonly remitted in full. Quote the practice statement explicitly.
Email the ATO via Online services for agents with: client identifiers, the form and period in question, dates of obstruction, supporting documents (medical certs, BoM disaster declarations), and a confirmation the form is now lodged.
Clients on your register by 31 October get the Lodgement Program dates — typically 15 May for individual ITRs, ~4-week extensions on Q1/Q3/Q4 BAS, and 25 June for FBT (electronic). Add new clients before the cut-off to preserve concessions.
Even modest balances grow noticeably when GIC sits around 11% p.a. compounding daily. On a $10k shortfall outstanding 6 months you accrue ~$580 in GIC — comfortably more than the base FTL penalty for a small entity in many cases.
A penalty unit is the standard increment the ATO uses to calculate administrative penalties under the Tax Administration Act 1953. From 7 November 2024 the rate is $330 per unit. The rate is indexed and reviewed periodically — always confirm the current value at ato.gov.au before issuing advice. The calculator above defaults to $330 but is editable so you can model past periods or anticipated indexation.
FTL applies when an entity fails to lodge an approved form (BAS, IAS, ITR, FBT return, TPAR, AS) by its due date. One penalty unit accrues for each 28-day period (or part thereof) the form is overdue, capped at 5 units. The unit count is then multiplied by the entity-size multiplier: 1× for small entities (<$1m turnover), 2× for medium ($1m–$20m), and 5× for large (>$20m) — meaning a large entity 5 months late faces up to 25 penalty units, currently $8,250.
Submit a written remission request to the ATO setting out the grounds under PS LA 2011/19. Strong grounds include serious illness or hospitalisation, natural disaster, family bereavement, agent error (with corroboration), or system outages preventing lodgement. Include dates, supporting documents, and a statement that the form has now been lodged. First-time offences with prompt rectification are commonly remitted in full; repeated late lodgements are harder to remit.
General Interest Charge (GIC) applies to unpaid tax liabilities and runs from the original due date. Shortfall Interest Charge (SIC) is a lower rate that applies to tax shortfalls revealed by an amended assessment — it covers the period between the original assessment and the amendment, after which GIC takes over. SIC is roughly GIC minus 3 percentage points. Both compound daily. This calculator estimates GIC; SIC would substitute a lower rate over the relevant window.
Registered tax agents access the Lodgement Program, which extends due dates for clients on their register by 31 October. Typical concessions: individual ITRs to 15 May (or 5 June with payment-on-time), Q1/Q3/Q4 BAS by ~4 weeks, FBT returns to 25 June (electronic), and company/SMSF returns generally to 28 February or 15 May depending on risk profile. Self-lodgers cannot access these dates. See the OneBookPlus Lodgement Deadline Calendar for the full grid.
The Lodgement Program is the ATO's published schedule of concessional due dates for tax agents who lodge electronically and maintain an on-time performance benchmark (currently 85% of forms lodged by the program due date). Agents who drop below the benchmark risk losing concessions — a powerful reason to triage clients early and request remission promptly when slippage occurs. New clients added to the agent register by 31 October generally retain access to the concessional dates.
OneBookPlus is the all-in-one platform for Australian tax agents — client registers, lodgement tracking, deadline reminders, and engagement workflows in one place.
Last reviewed and updated: by Bishal Shrestha
About the author
Founder & CEO, OneBookPlus
Bishal has over a decade of experience in digital marketing, web development, and small business consulting across Australia. Bishal has reviewed FTL penalty remission requests and GIC compounding with TPB-registered practitioners.
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