BAS Changes & ATO Updates 2026: What Perth Businesses Need to Know

For many Perth business owners, BAS lodgement has always felt like a routine admin job something you do at the end of the quarter, tick off, and move on. In 2026, that mindset no longer works.

The BAS Changes & ATO Updates 2026 reflect a much broader shift by the Australian Taxation Office. Compliance is no longer reactive. It’s continuous, data-driven, and far more visible than it used to be. Even small inconsistencies can now attract attention if the numbers don’t line up across systems.

For businesses operating in Western Australia particularly small and medium enterprises understanding what has changed is the difference between staying compliant quietly and dealing with ATO follow-ups you didn’t see coming.

This article explains what’s happening, why the ATO is tightening controls, and what Perth businesses should realistically be doing this year.

The Bigger Picture Behind ATO Changes in 2026

The ATO isn’t changing BAS rules just for the sake of it. The real driver is data.

In 2026, the ATO has access to more third-party information than ever before. Bank feeds, payroll reports, merchant facilities, and GST data from other businesses are all compared against what you lodge. When figures don’t match, it stands out immediately.

This doesn’t mean every mistake leads to penalties. But it does mean the margin for repeated errors is shrinking especially for businesses that lodge late, correct often, or don’t respond quickly to ATO correspondence.

How BAS Changes & ATO Updates 2026 Affect Perth Businesses

Perth has a high concentration of trades, contractors, hospitality operators, and professional service firms. These industries often deal with variable income, subcontractors, and mixed GST treatments all areas the ATO now monitors more closely.

Under the BAS Changes & ATO Updates 2026, businesses are expected to:

• Lodge consistently and on time
• Report GST accurately across all expense types
• Ensure payroll data aligns with BAS figures
• Maintain records that can be verified quickly

If your business relies on manual processes or outdated systems, you’re more exposed than you may realise.

GST Reporting: Where Most Businesses Still Get Caught

GST mistakes remain one of the most common BAS issues across Australia. In 2026, the ATO is particularly focused on:

• Claiming GST on expenses that are partly private
• Incorrectly claiming GST on GST-free items
• Overstating credits due to poor record-keeping

These errors are rarely intentional. They usually come from rushed lodgements or misunderstanding how GST applies to certain costs. This is where professional bas agent services continue to play an important role especially for businesses with complex or mixed expenses.

Payroll, PAYG and Why Reconciliation Matters More Than Ever

Single Touch Payroll has quietly changed how the ATO views wages and PAYG. What used to be checked annually is now monitored throughout the year.

If wages reported through payroll don’t align with PAYG amounts reported in BAS, the discrepancy is flagged automatically. This is a common issue for Perth businesses that:

• Use contractors alongside employees
• Have irregular pay cycles
• Experience high staff turnover

The key takeaway for 2026 is simple: payroll and BAS can no longer be treated as separate systems.

Digital Records Are No Longer “Optional”

While the ATO hasn’t banned paper records, relying on them in 2026 is risky. Digital accounting systems make it easier to:

• Track income accurately
• Categorise expenses correctly
• Respond quickly if the ATO asks questions

Businesses still using spreadsheets or manual methods often struggle to explain discrepancies when reviews occur. That delay alone can escalate a simple query into a compliance issue.

Business Structures and How They’re Affected

• Sole Traders: Many sole traders in Perth still mix personal and business transactions. That approach is becoming increasingly problematic. BAS errors can flow directly into individual returns, especially when working with a Personal Tax Agent who must reconcile everything accurately.
• Partnerships: Partnerships face extra pressure because BAS errors don’t just affect one person. They can delay or complicate a Partnership Tax Return, creating flow-on problems for every partner involved.
• Companies and Trusts: For companies and trusts, consistency is everything. BAS figures must align with payroll, financial statements, and annual tax returns. Under the BAS Changes & ATO Updates 2026, mismatches are far more visible than before.

Late Lodgements: Less Tolerance in 2026

Late BAS lodgement is still common, but the ATO’s patience is thinner. Businesses that repeatedly lodge late or ignore reminders are more likely to face penalties.

If you already have a Late tax Return or overdue BAS statements, acting early makes a big difference. In some situations, eligible businesses may still access the ATO amnesty late tax returns pathway, but only if disclosures are voluntary and timely.

Waiting until the ATO contacts you is rarely the best option.

Managing ATO Debt Without Making It Worse

Cash flow remains tight for many Perth businesses. The ATO understands this but only if you engage.

Businesses that communicate early, lodge correctly, and enter payment arrangements are generally treated far more favourably. Professional tax agent services can help structure those discussions and prevent issues from escalating unnecessarily.

• Practical Ways to Reduce Risk This Year
• To Avoid Ato Fines, Perth businesses should focus on a few core habits:
• Lodge BAS on time, even if payment can’t be made immediately
• Review GST treatment regularly, not just at lodgement time
• Reconcile payroll and BAS figures monthly
• Keep digital records organised and accessible
• Respond quickly to ATO letters

These steps aren’t complicated, but they are effective.

Are Professional Fees Worth It?

Many business owners hesitate because of cost. But understanding tax agent fees properly shows that professional support often saves money by preventing errors, penalties, and wasted time.

Most fees are tax-deductible, and the peace of mind alone is valuable for many business owners.

What Perth Businesses Should Do Next

If you haven’t reviewed your BAS processes recently, now is the time. Before the next reporting cycle:

• Check your GST classifications
• Make sure payroll and BAS data match
• Upgrade outdated systems
• Address any outstanding obligations

Staying ahead of the BAS Changes & ATO Updates 2026 is far easier than fixing problems after the ATO gets involved.

Final Thoughts

The ATO isn’t trying to catch businesses out but it is expecting higher standards. The BAS Changes & ATO Updates 2026 make it clear that accuracy, consistency, and engagement matter more than ever.

Perth businesses that adapt early, keep good records, and seek advice when needed will be in a far stronger position moving forward.