BAS Lodgement for Residential Builders
Quarterly BAS is due 28 October, 28 February, 28 April and 28 July, with about four extra weeks through an agent. The TPAR is due 28 August and the ATO data-matches it.
What it is
The BAS is the one form where a builder''s GST, PAYG withholding and PAYG instalments all land. Most builders treat it as a GST form. It is not, and the parts they forget are the parts that generate penalties.
What actually goes on it
| Label | What it reports |
|---|---|
| G1 | Total sales including GST |
| 1A | GST on sales |
| 1B | GST on purchases |
| W1 | Total salary, wages and other payments |
| W2 | Amounts withheld from W1 |
| 5A | PAYG income tax instalment |
1A minus 1B is your GST position. W2 is tax you took out of your crew''s pay and are holding for the ATO. 5A is a prepayment against your own income tax, worked out from your last return.
Cycles and due dates
Your GST cycle follows turnover. Quarterly if GST turnover is under $20 million and the ATO has not directed you to report monthly. Monthly if it is $20 million or more, or you choose to. Annually if you are voluntarily registered and turnover is under $75,000. Nearly every residential builder is quarterly.
| Quarter | Due |
|---|---|
| 1. July to September | 28 October |
| 2. October to December | 28 February |
| 3. January to March | 28 April |
| 4. April to June | 28 July |
Monthly BAS is due the 21st of the following month. The annual GST return is due 31 October.
The agent concession
Lodge online yourself and you may get an extra 2 weeks. Lodge electronically through a registered tax or BAS agent and the concession runs to about four weeks.
| Quarter | Standard | Via agent |
|---|---|---|
| Q4 2025-26 | 28 July 2026 | 25 August 2026 |
| Q1 2026-27 | 28 October 2026 | 25 November 2026 |
| Q2 2026-27 | 28 February 2027 | not applicable |
| Q3 2026-27 | 28 April 2027 | 26 May 2027 |
| Q4 2026-27 | 28 July 2027 | 25 August 2027 |
Quarter 2 gets nothing because the 28 February date already carries a one-month extension. The concession also only applies where your previous statement was lodged electronically.
The TPAR, which is the one that bites
If you run a business primarily in the building and construction industry, pay contractors or subcontractors for building and construction services and hold an ABN, you must lodge a Taxable payments annual report by 28 August each year.
You are primarily in building and construction if any of these apply: 50 per cent or more of your business income this year comes from building and construction services, 50 per cent or more of your business activity this year relates to them, or 50 per cent or more of your income last year did.
Note that last limb. A cabinet maker who drops under 50 per cent this year still lodges, because last year was above it.
The TPAR is a third-party data report and the ATO matches it against what your subbies declare. The usual mercy does not reach it either. The ATO generally will not issue a failure to lodge penalty for a late activity statement that produces a refund or a nil result, but that exclusion does not extend to third-party data reports like the TPAR.
The definition is wide. Bricklaying, concreting, plumbing, electrical, painting, tiling, roofing, landscaping construction, engineering, surveying, project management and architectural work all count. Wet hire, meaning plant with an operator, counts. Dry hire does not.
Super, penalties and interest
Payday Super is in force from 1 July 2026. Contributions must be received by the fund within 7 business days of each qualifying earnings payment, and fund receipt is the test, so clearing house lag counts against you. Super has stopped being a quarterly job that lines up with the BAS.
The failure to lodge penalty is one penalty unit for every 28 days or part thereof that a document is overdue, capped at 5 units. A penalty unit is $364 for infringements on or after 1 July 2026, so a small builder''s ceiling is $1,820 per late document. Medium withholders double that and large withholders multiply by five.
General interest charge runs on unpaid amounts, worked out daily on a compounding basis, at a rate reviewed quarterly. GIC incurred on or after 1 July 2025 cannot be claimed as a deduction. Price that in: paying late now costs you the full interest, not the after-tax interest.
If you use a registered agent, safe harbour may spare you the FTL penalty where you gave them everything needed to lodge on time and their failure was not reckless.
Fixing one
A mistake is an amount that was incorrect when you lodged. An adjustment is an amount that was correct at the time but changed later, such as a cancelled sale or a price change.
Many GST mistakes can be corrected in your next BAS, on conditions that turn on whether it is a credit or a debit error. If it does not fit, lodge a revision of the original statement. Adjustments generally go in the current period''s statement, not the old one.
Citations
- [1]
Due dates for lodging and paying your BAS
governmentAustralian Taxation Office · AU · accessed 17/07/2026
Quarterly - if your GST turnover is less than $20 million - and we have not told you that you must report monthly. Monthly - if your GST turnover is $20 million or more - or you choose to report GST monthly. Annually - if you are voluntarily registered for GST and your GST turnover is under $75,000. ... Due date for each quarter: 1. July, August and September, 28 October; 2. October, November and December, 28 February; 3. January, February and March, 28 April; 4. April, May and June, 28 July. ... If you lodge online, you may be eligible for an extra 2 weeks to lodge and pay your quarterly BAS. ... A later lodgment and payment due date does not apply for quarter 2 because the due date already includes a one-month extension. ... The due date to lodge and pay your monthly BAS is the 21st day of the month following the end of the taxable period. ... The due date to lodge and pay your annual GST return is 31 October.
- [2]
BAS agent lodgment program 2026-27
governmentAustralian Taxation Office · AU · accessed 17/07/2026
Table 2: BAS agent due dates - quarterly lodgment obligation. Quarter 4, 2025-26: original due date 28 July 2026, BAS agent concession 25 August 2026. Quarter 1, 2026-27: 28 October 2026, concession 25 November 2026. Quarter 2, 2026-27: 28 February 2027, Not applicable. Quarter 3, 2026-27: 28 April 2027, concession 26 May 2027. Quarter 4, 2026-27: 28 July 2027, concession 25 August 2027. ... The lodgment program due dates will be applied to eligible quarterly activity statements ... that generate after you've lodged your client's previous activity statement electronically.
- [3]
Building and construction services (TPAR)
governmentAustralian Taxation Office · AU · accessed 17/07/2026
If you are running a business primarily in the building and construction industry, you must lodge a Taxable payments annual report (TPAR) if you: make payments to contractors or subcontractors for building and construction services; have an Australian business number (ABN). ... Each year, you must: review if you need to lodge a TPAR; report these payments to us on your TPAR by 28 August. You are considered to be a business that primarily operates in building and construction services if any apply: in the current financial year, 50% or more of your business income is earned from providing building and construction services; in the current financial year, 50% or more of your business activity relates to building and construction services; in the financial year immediately before the current financial year, 50% or more of your business income was earned from providing building and construction services. ... Wet hire is a building and construction service.
- [4]
Failure to lodge on time penalty
governmentAustralian Taxation Office · AU · accessed 17/07/2026
The base FTL penalty is calculated at the rate of one penalty unit for every 28 days (or part thereof) that the document is overdue, up to a maximum of 5 penalty units. ... The base penalty is multiplied by 2 for an entity that is a 'medium withholder' ... A base penalty is multiplied by 5 for an entity that is a 'large withholder'. ... Generally, we will not issue you with an FTL penalty notice for a late-lodged tax return, FBT return, annual GST return or activity statement if the lodgment results in either a refund or a nil result, unless: ... the unlodged document is a third-party data report, such as a taxable payments annual report. ... If you engaged a registered tax or BAS agent to lodge your return or statement, you won't be liable for FTL penalty if both of the following apply: you can show that you provided the agent with all relevant tax information to enable them to lodge the return or statement by the due date; the agent's failure to lodge the return or statement was not because they were reckless or intentionally disregarded the tax law.
- [5]
governmentAustralian Taxation Office · AU · accessed 17/07/2026
Table: Penalty unit. When infringement occurred / Penalty unit amount ($): On or after 1 July 2026, 364; 7 November 2024 to 30 June 2026, 330; 1 July 2023 to 6 November 2024, 313. ... You can't claim a deduction for penalties we impose.
- [6]
governmentAustralian Taxation Office · AU · accessed 17/07/2026
General interest charge (GIC) is applied to unpaid tax liabilities and is worked out daily on a compounding basis. ... We review the GIC rate quarterly. GIC is calculated on a daily compounding basis on the amount overdue. ... GIC incurred on or after 1 July 2025 can't be claimed as a deduction. ... However, GIC incurred before 1 July 2025 can be claimed as a deduction in your tax return for the financial year in which the GIC is incurred.
How this was researched
This entry was drafted from primary Australian sources (legislation, regulator publications and industry guidance) and reviewed and signed off by Hunter Jacobs, Director, TradeForm. Citations link to the source documents you can verify yourself. The entry is re-verified on a cadence and automatically flagged for review when a watched source changes.
Disclaimer
This is general information about Australian construction and business topics. It is not legal, engineering, or financial advice. Laws and standards change. Verify current requirements with a licensed professional in your jurisdiction before relying on this content.