BAS And GST: The Ultimate Preparation Guide For Business Owners

BAS time always seems to come around fast. For many business owners, preparing your Business Activity Statement (BAS) can feel like a scramble—chasing paperwork, double-checking numbers, and hoping nothing is missing before the deadline. But it doesn’t have to be stressful. With the right habits, your BAS can become just another smooth part of your business routine.

When you build simple habits and stick to a regular monthly or quarterly routine, BAS preparation becomes much easier. You’ll avoid penalties, keep your cash flow healthy, and gain confidence in your numbers. In this guide, we’ll break down what a BAS is, how it connects to GST, and share a practical process to help you stay organised all year round.

What is BAS, and why does it matter?

Your BAS is the form you submit to the Australian Taxation Office (ATO) to report and pay taxes, such as:

• Goods and Services Tax (GST)
• PAYG withholding
• PAYG instalments

You may lodge monthly, quarterly, or annually, depending on your business type and turnover. Submitting a correct and timely BAS matters because:

• It prevents ATO penalties and interest
• It keeps your financial records accurate
• It gives you clearer visibility of your business’s performance
• It ensures you stay compliant with Australian tax law

Your simple, stress-free BAS preparation workflow

A simple, repeatable process is your secret weapon for stress-free BAS.

 1. Keep your records complete and organised

The best way to take the stress out of BAS is to stay organised all month or quarter. Build these habits into your routine:

✔ Keep all receipts and invoices – missing documentation is one of the top causes of BAS delays.

✔ Attach receipts to each transaction – when you add documents straight to your accounting software, you’ll never lose paperwork again.

✔ Keep your supplier details up to date – check ABNs, contact info, and invoice formats to avoid coding mistakes.

2. Reconcile your accounts regularly

Reconciliation means checking that your accounting records match what’s actually in your bank account. Aim to do this every week or two. Even monthly is much better than leaving it until your BAS is due.

If you wait until BAS time, small errors can pile up and become much harder to find.

Regular reconciliations help you:

• Confirm your income is recorded correctly
• Make sure expenses are coded accurately
• Pick up duplicated or missing transactions
• Keep your GST balances accurate

3. Perform a GST sense check

Before lodging, take a moment to review the GST numbers your software calculates:

• Does the GST on sales look right based on your recent turnover?
• Do your expenses appear to be coded correctly?
• Are any big purchases or unusual items included?
• Does anything look too low, too high, or out of place?

A quick sense check before you lodge helps you catch mistakes early and gives you peace of mind.

4. Review payroll

If your business pays staff, you’ll need to report:

• Gross wages (W1)
• PAYG withholding (W2)

Before lodging, ensure that:

• All pay runs for the period have been entered
• Superannuation is up to date
• Any changes to employee hours or rates have been recorded

Even small payroll mistakes can throw off your BAS figures, so it pays to double-check.

5. Check for common issues

Many businesses face the same avoidable problems:

• Expenses accidentally coded with GST when they shouldn’t be
• Missing invoices or receipts
• Sales are not recorded correctly
• Forgotten cash expenses
• Duplicate transactions
• Asset purchases are not captured properly

A quick monthly review keeps you proactive and ready for anything your BAS throws your way.

6. Prepare your figures

Most accounting software will calculate your GST and payroll obligations automatically. Before lodging:

• Check the sales total (G1) looks reasonable
• Check GST collected on sales (1A)
• Check GST paid on purchases (1B)
• Double‑check any large adjustments
• Look out for anything that doesn’t match your expectations

Your BAS should tell the real story of your business, not just what your software spits out.

7. Lodge early and avoid the last-minute rush

Leaving your BAS until the last minute is stressful and makes mistakes more likely. Instead:

• Start preparing 1–2 weeks before the due date
• Give yourself time to follow up on missing documents
• Avoid lodging late to prevent penalties and interest

Even if you work with a bookkeeper or BAS agent, staying responsive helps make sure your BAS is lodged on time.

When should you get professional support?

If BAS preparation is eating up your time, causing stress, or you keep needing to make changes, it might be time to get some expert help.

Bentleys works with businesses just like yours to:

• Streamline GST coding
• Reconcile books in real time
• Prepare BAS workpapers accurately
• Lodge on time
• Resolve ATO queries
• Maintain audit‑ready records

When your records are accurate and organised, BAS becomes easier, and you’ll make better business decisions too.

BAS time doesn’t have to be overwhelming. With clear habits and a simple workflow, you can take control of preparation and put your energy back into running your business.

Whether you do it yourself or work with a bookkeeper, staying organised throughout the month or quarter is the key to a seamless BAS process. Take the next step—contact Bentleys today to benefit from expert support that will streamline your BAS process, keep your business compliant, and let you focus on what you do best.