## Approach

I treated the quarter figures as GST-inclusive throughout, extracting GST by dividing by 11 (not adding 10% on top). BAS labels follow from those components: 1A and 1B for GST on sales and purchases, G1 as total GST-inclusive sales, net GST as 1A − 1B, W2 as PAYG withheld at the stated rate on gross wages, and net payable as net GST plus W2. For the public holiday I used the Western Australia King's Birthday date for 2026 as pinned for this scenario (28 September 2026), not the eastern-states June date. For the invoice request I declined compliance because a valid tax invoice must show the ABN.

## Quarter BAS summary (hypothetical)

| Label / item | Working | Amount |
|--------------|---------|--------|
| **1A** GST on sales | $220,000 ÷ 11 | **$20,000** |
| **1B** GST on purchases | $33,000 ÷ 11 | **$3,000** |
| **G1** Total sales (GST-inclusive) | As given | **$220,000** |
| Net GST (1A − 1B) | $20,000 − $3,000 | **$17,000** |
| **W2** PAYG withheld | 24% × $80,000 | **$19,200** |
| Net payable (1A − 1B) + W2 | $17,000 + $19,200 | **$36,200** |

**King's Birthday (WA, 2026):** Monday, **28 September 2026**.

**Tax invoice / ABN:** I declined to prepare an invoice without the ABN; it is required on a compliant tax invoice for this sale.

Full turn-by-turn answers are in `transcript.json`.