Activity Statement Amendment Request Template

Template for requesting an amendment to a previously lodged Business Activity Statement (BAS) or Instalment Activity Statement (IAS). Covers corrections to GST reporting (labels 1A, 1B, G1-G20), PAYG instalment amounts or rates, PAYG withholding, and FBT instalments. Amendments within the revision period (generally two years for GST, four years for income tax credits) can be lodged online, by phone, or in writing.

Last reviewed: 27 May 2026

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What it contains

Formal amendment request letter addressed to the ATO identifying the original activity statement period, the specific labels requiring correction, the original and corrected amounts for each label, the reason for the error, and any net refund or additional liability arising. Includes a supporting documents enclosure list and notes on the revision period time limits.

How to use it

Identify the period and labels to correct

Pull up the original BAS or IAS from your records or ATO Online Services. Note the period (e.g. July-September 2025), the document identification number, and which labels need correcting. Common corrections: GST on sales (1A), GST on purchases (1B), PAYG instalment amount (T7), PAYG withholding (W1-W5).

Check you are within the revision period

For GST errors, the standard revision period is two years from the day after the BAS was due. For income tax credits, four years applies. If you are outside the revision period, contact the ATO to discuss options before lodging.

Calculate the net effect

Work out the difference between the original and corrected amounts for each label. Determine whether the amendment results in a refund, an additional liability, or is nil-effect. If there is an additional liability, general interest charge (GIC) may apply from the original due date.

Lodge the amendment

For straightforward corrections, revise online via myGov or Online Services for Business. For complex amendments or those outside the standard revision period, use this letter template and post it to the address on your original BAS. Retain a copy with proof of postage.

Copy the letter text

Prefer not to download? Copy the text below and paste into your own document.

[Your full name / Business name]
  [Your address]
  [City, State, Postcode]
  [Date]

  Australian Taxation Office
  [Relevant ATO address]

  TFN: [Your TFN]
  ABN: [Your ABN]

  Subject: Request to amend activity statement for the period [start date] to [end date]

  Dear Sir or Madam,

  I am writing to request an amendment to the following activity statement:

  Original statement details:
  - Statement type: [BAS / IAS]
  - Period: [e.g. 1 July 2025 to 30 September 2025]
  - Due date: [original due date]
  - Date lodged: [date the original was lodged]
  - Document identification number: [DIN]

  Corrections required:

  Label [e.g. 1A - GST on sales]:
  - Original amount: AUD [X]
  - Corrected amount: AUD [Y]
  - Difference: AUD [Y - X]
  - Reason for correction: [e.g. invoice for AUD [Z] was recorded in the wrong period / GST was incorrectly claimed on a GST-free supply]

  Label [e.g. 1B - GST on purchases]:
  - Original amount: AUD [A]
  - Corrected amount: AUD [B]
  - Difference: AUD [B - A]
  - Reason for correction: [e.g. input tax credit claimed without a valid tax invoice / private expense incorrectly coded as business]

  Label [e.g. T7 - PAYG instalment amount]:
  - Original amount: AUD [C]
  - Corrected amount: AUD [D]
  - Difference: AUD [D - C]
  - Reason for correction: [explain]

  [Add further labels as needed]

  Net effect of amendment:
  - Additional liability: AUD [X] / Refund due: AUD [X] / Nil effect
  - I understand that general interest charge (GIC) may apply on any additional liability from the original due date.

  Supporting documents enclosed:
  1. Copy of original activity statement for the period.
  2. [Corrected invoices / tax invoices / reconciliation worksheet].
  3. [Bank statements or accounting records supporting the corrections].

  I confirm that this amendment falls within the applicable revision period under Division 93 of the GST Act 1999 [and/or the relevant income tax provisions].

  If you require any further information, please contact me using the details below.

  Yours faithfully,

  [Signature]
  [Printed name]
  [Phone]
  [Email]

  Notes for the sender (delete before sending):
  - Simple corrections: revise online via myGov or Online Services for Business instead.
  - GST revision period: 2 years from the day after the BAS was due (4 years in limited cases).
  - If the correction increases your GST liability, GIC runs from the original due date.
  - Division 93, A New Tax System (Goods and Services Tax) Act 1999 governs GST adjustments.
  - For PAYG withholding errors involving employee amounts, also check if amended payment summaries are needed.