What Records Does a Business Need for BAS?

Understanding BAS record keeping

The records behind a BAS serve two purposes: they let the statement be prepared accurately, and they evidence the figures if they are ever queried.

Australian businesses are generally required to keep records that explain their transactions, in English or in a form that can be readily converted, for a minimum period set by the ATO. The specific requirements vary by record type, so confirm them on the ATO website or with your adviser.

Electronic records are acceptable, which in practice means attaching documents in your accounting software is usually the most reliable filing system available to a small business.

Sales invoices and income records

You need a complete record of what the business sold or earned during the period, with enough detail to show how each amount was treated.

• Sales invoices issued, including tax invoices where required
• Receipts or settlement reports from point-of-sale, e-commerce and payment platforms
• Credit notes, refunds and adjustments
• Records of income that is not from ordinary sales, such as grants, insurance proceeds or asset sales
• Details of any sales treated as GST-free or input taxed, and the basis for that treatment

Purchase invoices and expense receipts

Expense records need to show what was bought, from whom, when, and how much GST (if any) was involved.

• Supplier tax invoices and receipts
• Records of purchases paid personally by an owner on behalf of the business
• Contracts, hire purchase and lease documents for financed items
• Asset purchase documentation
• Records supporting any apportionment between business and private use

GST information

If you are registered for GST, keep the information that supports the GST position taken on each transaction. For purchases, this generally means holding a valid tax invoice where one is required before claiming a GST credit.

Also keep records of transactions where GST treatment is unusual or was determined by advice — imports, international services, mixed supplies and property transactions are common examples.

Bank statements

Statements for every bank account the business uses are needed to confirm that the accounting records are complete and reconciled. That includes secondary accounts, savings accounts used for tax or super set-asides, and any loan or overdraft facilities.

Credit-card statements

Business credit-card and charge-card statements are part of the record set, along with the receipts supporting each purchase. Cards are where documentation gaps most often appear, because purchases are small, frequent and easy to forget.

Payroll records

Where a statement includes withholding from wages, payroll records support the figures reported.

• Payroll reports for each pay run in the period
• Payment summaries or Single Touch Payroll reporting records
• Tax file number declarations and employee tax treatment details
• Superannuation calculations and payment records
• Records of allowances, deductions, terminations and leave payments

PAYG withholding information

Withholding is not limited to employees. Keep records of amounts withheld from other payments as well — for example, payments to contractors under a voluntary agreement, or payments to suppliers who did not quote an ABN where withholding applies. The rules for these situations are specific; confirm what applies to you.

Accounting software records

Your accounting file is itself a record. Keep the general ledger, transaction listings, GST reports, aged receivables and payables reports, and the reconciliation reports for the period.

If you change software or providers, make sure the historical data remains accessible for the full retention period. Losing access to an old subscription can mean losing access to records you are required to keep.

Adjustments and unusual transactions

Adjustments are the transactions most likely to be questioned later and least likely to be remembered. Keep a short written explanation with each one.

• Journal entries and the reason for them
• Corrections to prior periods
• Bad debts written off
• Barter or non-cash transactions
• Related-party transactions
• Insurance claims, settlements and one-off receipts

Supporting documentation

Beyond invoices and statements, keep the material that explains the context: supplier and customer contracts, loan agreements, lease documents, and correspondence about anything unusual.

Where a treatment was based on advice, keep the advice with the record. It is the difference between a documented position and an unexplained figure.

Organising records before BAS preparation

The practical goal is that anyone preparing the statement can find the support for any figure without asking you. That usually means documents attached to transactions in the accounting file, a consistent naming approach for anything stored outside it, and a single place for open queries.

If you are working with an accountant or registered BAS agent, ask what format they want the records in before the period ends rather than after.

Common missing records

• Tax invoices for larger purchases, particularly one-off equipment
• Receipts for card purchases made while travelling
• Business expenses paid from a personal account
• Settlement reports from payment platforms
• Loan and finance agreements for newly financed assets
• Documentation for journals and prior-period corrections
• Superannuation payment confirmations

Practical BAS records checklist

1. Sales invoices and platform settlement reports for the period
2. Credit notes, refunds and adjustments
3. Supplier tax invoices and receipts, including owner-paid purchases
4. Bank statements for every account, covering the full period
5. Credit-card and payment-platform statements
6. Payroll reports, STP records and superannuation payment evidence
7. Records of any other amounts withheld
8. General ledger, GST and reconciliation reports from your software
9. Documentation and explanations for journals and unusual transactions
10. Contracts, loan and lease agreements relevant to the period

When to ask an accountant or BAS professional for assistance

If records are incomplete, if you are unsure how a transaction should be treated, or if the business has changed in a way that affects its registrations, it is worth getting help before the statement is prepared rather than after it is lodged.

Preparing or lodging a BAS for a fee is restricted to registered BAS agents and registered tax agents under Australian law.

Related services

Keep reading

• BAS Preparation Checklist for Australian Businesses

  A step-by-step process for getting your records BAS-ready: what to reconcile, what to review, and the record-keeping problems that most often hold up preparation.

• Monthly Bookkeeping Checklist for Australian Small Businesses

  A month-end routine that keeps your records reliable: reconciliations, income and expense coding, debtors and creditors, payroll and super records, GST records and the reports worth reading.