ATO Interest · Calculator

ATO Interest Calculator Australia 2026

Estimate ATO General Interest Charge on overdue tax or Shortfall Interest Charge on an amended assessment. Uses official daily rates for every date and models partial GIC payments.

GIC + SICDaily CompoundingOfficial ATO Rates
01INPUTS

General Interest Charge on an unpaid tax debt

Usually the payment due date; this day is included

The final day included in the estimate

Each payment is applied before that day’s estimated charge. ATO account allocation can differ.

Official ATO rates are available here from 1 July 2024 through 30 September 2026. No future rate is assumed.
02RESULTS
Awaiting input

Enter the amount and charge period to calculate GIC

Official ATO GIC rates

Published quarterly; latest available period ends 30 September 2026.

QuarterPeriodAnnualDaily
Q1 FY2026-27 (Jul–Sep 2026)1 July 202630 Sept 202611.43%0.03131507%
Q4 FY2025-26 (Apr–Jun 2026)1 Apr 202630 June 202610.96%0.03002740%
Q3 FY2025-26 (Jan–Mar 2026)1 Jan 202631 Mar 202610.65%0.02917808%
Q2 FY2025-26 (Oct–Dec 2025)1 Oct 202531 Dec 202510.61%0.02906849%
Q1 FY2025-26 (Jul–Sep 2025)1 July 202530 Sept 202510.78%0.02953425%
Q4 FY2024-25 (Apr–Jun 2025)1 Apr 202530 June 202511.17%0.03060274%
Q3 FY2024-25 (Jan–Mar 2025)1 Jan 202531 Mar 202511.42%0.03128767%
Q2 FY2024-25 (Oct–Dec 2024)1 Oct 202431 Dec 202411.38%0.03109290%
Q1 FY2024-25 (Jul–Sep 2024)1 July 202430 Sept 202411.36%0.03103825%
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What is GIC

What is the General Interest Charge (GIC)?

The General Interest Charge is an interest charge the ATO applies when you have an outstanding tax liability that is overdue. Its daily compounding and rate rules are set out in sections 8AAC and 8AAD of the Taxation Administration Act 1953 and it applies to late or unpaid income tax, GST, PAYG instalments, and many other tax obligations.

The GIC period starts at the beginning of the day payment was due. It is applied on a daily compounding basis — each day's charge is calculated on the unpaid balance including unpaid GIC from earlier days.

The current GIC rate for Q1 2026-27 (1 July – 30 September 2026) is 11.43% per annum.

How it's calculated

How GIC is Calculated

GIC uses daily compounding — each day's charge is added to the balance, and the next day's charge is calculated on the new higher balance.

Step 1 Select the exact daily rate published by the ATO for that date
Step 2 Multiply the unpaid balance (debt + accumulated GIC) by that daily rate
Step 3 Add that day's GIC to the running balance
Step 4 Repeat each day until paid in full

Worked Example — $10,000 debt at 11.43%

DayOpening BalanceDaily GICClosing Balance
Day 1$10,000.00$3.13$10,003.13
Day 2$10,003.13$3.13$10,006.26
Day 30$10,094.37

Over these 30 charge days, the official July–September 2026 daily rate produces $94.37 of GIC. The calculator uses unrounded running balances.

GIC deductibility

GIC is No Longer Tax-Deductible

From 1 July 2025, GIC is no longer deductible. Previously it was deductible under section 8-1 of the ITAA 1997.

GIC incurred before 1 July 2025 May remain deductible under the earlier rules
GIC incurred from 1 July 2025 Not deductible (even for pre-2025 debts)
SIC (Shortfall Interest Charge) Also no longer deductible

Compare carefully: Interest incurred from 1 July 2025 no longer produces a tax deduction. If considering another form of finance, compare total costs and obtain advice appropriate to your circumstances.

Reducing GIC

How to Reduce or Remit GIC

Pay the debt as soon as possible

The only way to stop GIC is to pay the full amount. Even partial payments reduce the balance on which GIC is calculated. GIC at ~11.43% is higher than most commercial rates.

Request a payment plan

A payment plan does not stop GIC from accruing, but it prevents more serious collection action. The ATO may be more willing to consider remission if you are on a plan and meeting obligations.

Apply for GIC remission

The ATO can remit GIC under section 8AAG if extraordinary circumstances prevented payment (serious illness, natural disaster, ATO error, incorrect ATO advice). Lodge through myGov or via your tax agent.

Lodge on time even if you cannot pay

Always lodge returns and activity statements on time. Late lodgement adds a Failure to Lodge penalty on top of GIC. Lodging on time but paying late only attracts GIC.

GIC vs SIC

GIC vs Shortfall Interest Charge (SIC)

FeatureGICSIC
When it appliesLate or unpaid taxShortfall from amended assessments
Rate formulaBase rate + 7%Base rate + 3%
Rate (Jul–Sep 2026)11.43% p.a.7.43% p.a.
CompoundingDailyDaily
Tax-deductible from 1 Jul 2025NoNo

SIC generally runs from the original assessment payment due date through the day before the ATO gives notice of the amended assessment. GIC may then apply if the additional tax is not paid by its due date.

FAQ
What is the current ATO GIC rate?
The ATO-published GIC rate for Q1 2026-27 (July to September 2026) is 11.43% per annum, with a daily rate of 0.03131507%. The rate is updated quarterly.
How is GIC calculated?
GIC is calculated daily on the unpaid balance, including unpaid GIC from earlier days. The calculator uses the exact daily rate published by the ATO for each date and includes both the first and last GIC days entered.
Can I claim GIC as a tax deduction?
GIC and SIC incurred on or after 1 July 2025 are not tax-deductible, including charges relating to an older underlying tax debt. Charges incurred before that date remain subject to the earlier rules.
How do I stop GIC from accruing?
The only way to stop GIC from accruing is to pay the outstanding tax debt in full. Setting up a payment plan with the ATO does not stop GIC — it continues to accrue on the unpaid balance. However, paying as much as you can as soon as possible will reduce the balance on which GIC is calculated.
Can the ATO remit (cancel) GIC?
Yes, the ATO can remit (reduce or cancel) GIC in certain circumstances. You can apply for GIC remission if you experienced extraordinary circumstances beyond your control (such as serious illness or natural disaster), if the ATO contributed to a delay, or if it would be fair and reasonable to do so. The ATO considers each case on its merits.
What is the difference between GIC and SIC?
GIC applies to late or unpaid tax and uses the base rate plus 7 percentage points. SIC applies to additional tax from an amended assessment and uses the base rate plus 3 percentage points. For July to September 2026, the official rates are 11.43% GIC and 7.43% SIC.

Tax Accuracy & Sources

Reviewed: 17 July 2026 · Tax year: 2026-27

This calculator estimates GIC or SIC only for dates covered by published ATO rates. Actual account charges can differ because of payment posting, account allocation, remission and other adjustments.