BAS Setup

How this usually works

A good bas setup process begins with a short diagnostic: your ABN, GST registration date, business structure, payroll status, reporting frequency (monthly or quarterly), and current software (Xero, MYOB or QuickBooks).

From there the work splits into three layers:

• Immediate triage: stop any ongoing errors (wrong GST codes, duplicate bank rules, unmapped payroll categories) and stabilise reconciliations.
• Process design: configure tax settings, tax codes, bank rules, chart of accounts, payroll/STP and document the review and lodgement workflow.
• Ongoing review: quarterly/monthly checks, BAS preparation, agent review, client approval, and on-time lodgement to the ATO.

Australian context to keep in view

• BAS reports GST, PAYG withholding and sometimes PAYG instalments and other labels to the ATO.
• Choose cash or accrual GST carefully—this drives how revenue and expenses flow into BAS.
• STP-enabled payroll must align with PAYG withholding in BAS to avoid variance notices.
• Lodgement can be done by you via Online services for business, or by a registered BAS or tax agent who may access extended due dates.

If you already have overdue periods, see BAS Catch Up Services. If you suspect errors, read BAS Review or BAS Corrections. For routine submissions, go to BAS Lodgement.

BAS setup checklist

• ABN and registrations: confirm GST start date, PAYG withholding and PAYG instalments (if applicable).
• GST method and cycle: cash or accrual; monthly or quarterly reporting; fuel tax credits if relevant.
• Software configuration: correct tax codes (GST on income/expenses, GST free, export, input taxed); lock old periods; enable two-step approval if needed.
• Bank rules and reconciliations: avoid GST on transfers, repayments and owner drawings; reconcile to the period end.
• Payroll alignment: STP active, PAYG W mapping, super categories, leave and allowances mapped to correct tax treatment.
• Documents and audit trail: tax invoices, credit notes, import documentation, and clear supporting notes for BAS adjustments.
• Workflow: who prepares, who reviews (registered agent), approval method, due dates and payment process.

What to compare before you commit

If you need provider options suited to your size, see BAS Agent for Companies, BAS Agent for Small Business or BAS Agent for Sole Traders.

Common BAS setup mistakes to avoid

• Using GST on bank transfers, loan repayments or wages—these should be coded without GST.
• Incorrect cash vs accrual setting causing timing mismatches and ATO variance letters.
• Unmapped payroll categories leading to PAYG W not matching STP totals.
• Backdating changes without locking prior periods, creating silent rework across multiple BAS.
• Missing import GST documentation (e.g., deferred GST) or treating exports with GST incorrectly.

Timeframes and pricing signals

• Simple setup (new GST registration, single software, no payroll): often 1–3 business days once access and records are ready.
• Moderate setup (payroll/STP, multiple bank feeds, historic variances): typically 1–2 weeks including a first BAS review.
• Complex setup (multi-entity, corrections, migrations): staged plan with milestones, review points and clear sign-offs.

Pricing depends on scope and data quality. Expect fixed-fee setup for defined work, with separate fees for catch-up or corrections. For ongoing BAS lodgement, monthly or quarterly packages are common.

Best next steps

Write down the exact outcome you want: accurate GST, a lodged BAS, payroll alignment, software migration, or a full health check.

Shortlist providers who can show real tax code mapping examples, articulate the review process, and commit to a clear schedule before your next BAS is due.

Move into the most relevant subtopic before you make contact: BAS Lodgement, BAS Review, BAS Corrections or BAS Catch Up Services.