• 11 January, 2026

“GST Errors You Can’t Fix in a Later BAS Australia (2026 Guide)”

Making mistakes in your Business Activity Statement (BAS) is more common than you think. While some GST errors can be corrected in a future BAS, others cannot be fixed later—and getting this wrong can lead to penalties, interest charges, and ATO scrutiny.

In this guide, we explain which GST errors you can’t correct in a later BAS, why, and what you should do instead.

What Is a GST Error?

A GST error occurs when you make a mistake in reporting:

• GST collected on sales
• GST credits claimed on purchases
• GST adjustments

This can result in:

• Credit errors → Paying too much GST
• Debit errors → Paying too little GST

👉 Note: GST errors do not include mistakes related to fuel tax credits, wine equalisation tax, or luxury car tax.

Can You Fix GST Errors in a Later BAS?

Yes—but only if certain conditions are met.

Correcting GST errors in a future BAS is often easier than revising a previous BAS. However, you must:

• Be within the ATO review period
• Meet error value limits
• Not be under ATO compliance activity

If these conditions aren’t met, you’ll need to revise the original BAS instead.

GST Errors You CANNOT Fix in a Later BAS

Here are the key situations where corrections in a later BAS are not allowed:

1. When the ATO Is Conducting a Compliance Activity

You cannot correct errors in a later BAS if:

• The ATO has started a review, audit, or verification check
• The error relates to the period under investigation

What You Should Do:

• Disclose the error to the ATO
• Wait for guidance or formal approval

👉 The ATO may consider voluntary disclosure when determining penalties.

2. When the Error Has Already Been Corrected

You cannot fix the same GST error more than once.

This includes situations where:

• You already revised the original BAS
• You corrected it in another reporting period
• You partially corrected a debit error due to limits

👉 Any remaining amount cannot be corrected again later.

3. When You’ve Already Lodged a Later BAS

You cannot revise a lodged BAS to fix an earlier GST error.

Example:

• Error made in October BAS
• February BAS already lodged

❌ You cannot adjust February BAS
✔ You must correct it in the next BAS (e.g., April) if eligible

4. When Outside the Period of Review

If the error falls outside the ATO review period, you:

❌ Cannot correct it in a later BAS
✔ Must follow ATO amendment procedures

What Is an ATO Compliance Activity?

A compliance activity includes:

• ATO audits
• Reviews
• Record-keeping checks
• Verification processes

Once notified, restrictions apply to how you correct GST errors.

Why Correcting GST Errors Properly Matters

Incorrect handling can lead to:

• General Interest Charges (GIC)
• ATO penalties
• Increased audit risk
• Cash flow issues

Proper correction ensures compliance and avoids unnecessary costs.

Best Practices to Avoid GST Errors

✔ Maintain accurate and up-to-date records
✔ Reconcile BAS before lodgment
✔ Use reliable accounting software
✔ Understand GST classifications
✔ Seek professional advice when unsure

How Workpaper Can Help

At Workpaper Accounting Services, we help businesses:

• Identify and correct GST errors properly
• Lodge and revise BAS accurately
• Stay compliant with ATO regulations
• Reduce penalties and audit risks

Get Expert Help Today

Avoid costly GST mistakes with expert support.

Workpaper Accounting Services
🌐 Website: https://workpaper.com.au/

📞 Phone: 0485 825 915
📧 Email: info@workpaper.com.au

📍 Address: 7 Bridge St, Werribee, Victoria 3030, Australia