Can AI do your BAS?
AI can prepare, not lodge. An agent connected to ato-mcp builds a cited checklist for your reporting period: which labels apply, what to gather for each and when it's due, with the ATO page behind every line. You (or your BAS agent) still review the numbers and lodge.
When is your BAS due?
Most small businesses report quarterly. The standard due dates are:
| Quarter | Months covered | Due date |
|---|---|---|
| Quarter 1 | July, August and September | 28 October |
| Quarter 2 | October, November and December | 28 February |
| Quarter 3 | January, February and March | 28 April |
| Quarter 4 | April, May and June | 28 July |
Lodging online can add two extra weeks, except for quarter 2, whose due date already includes a one-month extension.
What goes on a Simpler BAS?
If your GST turnover is under $10 million you use Simpler BAS, which needs three GST labels:
- G1: total sales for the period.
- 1A: GST you collected on those sales.
- 1B: GST credits on business purchases (some purchases don't qualify).
Do you even need to lodge one?
Only if you're registered for GST. Registration becomes mandatory once your GST turnover reaches $75,000 ($150,000 for non-profits), or from day one if you drive taxis or do ride-sourcing, regardless of turnover.
What does the agent actually do?
Connected to ato-mcp, your agent calls bas_prep_checklist: a deterministic tool that reads your saved tax profile (reporting period, GST registration, structure) and returns a tiered checklist for the quarter: the labels that apply to you, the evidence to gather for each, the gotchas people hit, and the ATO source cited on every line. It prepares; you lodge.
The questions everyone asks
Can the agent lodge my BAS for me?
No. ato-mcp prepares: it builds the checklist, explains the labels and cites the ATO source behind each line. Lodgment happens in myGov, Online services for business, your accounting software or through your BAS agent.
Do I get more time if I lodge online or through an agent?
Usually. Lodging online can add two extra weeks to quarterly due dates, and registered tax or BAS agents have their own lodgment programs. The quarter 2 due date already includes a one-month extension, so no further online extension applies to it.
Is this tax advice?
No. ato-mcp is information infrastructure: it retrieves published ATO material and runs fixed, cited calculations. It does not consider your full circumstances and it is not a registered tax or BAS agent service. Verify material decisions with a registered agent.
Which AI agents work with it?
Anything that speaks MCP: Claude Code, Claude Desktop, ChatGPT, Codex, Gemini CLI, Cursor and VS Code all connect to the same endpoint with a browser sign-in.
Related reading: It's BAS time again and Can an AI agent find your tax deductions?