Is Checking Your Supplier’s ABN Worth Its Weight in Gold?
FOCUS: Why checking supplier ABNs protects your GST credits, BAS accuracy and business cash flow
When you receive a supplier invoice, it is easy to focus on the amount owing and move straight to payment. But before that invoice is approved, there is one golden check every business should make: is the supplier’s ABN valid, and are they registered for GST?
A supplier ABN check may feel like a small bookkeeping step, but it can protect your business from incorrect GST claims, invalid tax invoices, PAYG withholding issues and avoidable BAS corrections. Think of it as panning for gold before you bank the claim: a few minutes of checking can help separate compliant invoices from costly surprises.
Key Takeaways
- An ABN alone is not enough. To claim GST credits, the supplier generally needs to be registered for GST and you need a valid tax invoice.
- If a supplier does not quote a valid ABN, you may need to withhold 47% from the payment and send it to the ATO.
- For purchases over $82.50 including GST, you generally need a valid tax invoice before claiming a GST credit.
- For tax invoices of $1,000 or more, the buyer’s identity or ABN must also be shown.
- Overseas supplier invoices need extra care. GST rules differ for imported services, digital products and low-value imported goods.
- ABN Lookup helps confirm ABN status, business type and GST registration, but it does not verify bank account ownership or protect you from invoice fraud.
- Regular supplier checks are good business governance and can reduce BAS errors before they become bigger problems.
What is an ABN and why does it matter?
An Australian Business Number, or ABN, is a unique number used to identify a business when dealing with the ATO, other businesses and government agencies. ABN Lookup provides free access to public Australian Business Register information, including whether an ABN is active or cancelled, the business type, public ABR details and GST registration status.
That makes ABN Lookup a useful first stop before claiming GST or paying a new supplier.
However, an ABN is not the same as GST registration. A supplier may have an active ABN but not be registered for GST. If they are not registered, they generally cannot charge GST, and you generally cannot claim a GST credit on that purchase.
Why this matters for GST credits
GST is 10% on most goods and services sold or consumed in Australia. For GST-registered businesses, the GST included in business purchases may be claimable as a GST credit, provided the rules are met.
Business.gov.au explains GST as “a tax of 10% on most goods, services and other items sold or consumed in Australia.”
The ATO says you cannot claim GST credits for purchases from a supplier that is not registered, or required to be registered, for GST.
In plain English: if a supplier charges GST but is not registered for GST, the invoice may look polished, but the GST claim may be fool’s gold.
The golden rule: check both ABN and GST registration
Before claiming GST on a supplier invoice, check:
- The ABN is valid and active.
- The ABN belongs to the supplier named on the invoice.
- The supplier was registered for GST at the time of the supply.
- The invoice is a valid tax invoice.
- The purchase was for your business.
- The GST amount has been calculated correctly.
The ATO recommends checking contractor and supplier details, including ABN, name and GST registration, using ABN Lookup or the ATO app.
What makes a valid tax invoice?
A valid tax invoice is more than just an invoice with the words “Tax Invoice” at the top.
Taxable sales under $1,000, the ATO says a tax invoice must include enough information to clearly determine details such as the seller’s identity, the seller’s ABN, the date of issue, a description of what was sold, the GST amount or a statement that the price includes GST, and the extent to which each sale is taxable.
For sales of $1,000 or more, the tax invoice must also show the buyer’s identity or ABN.
For GST credit claims, the ATO says: “You must have a tax invoice to claim a GST credit for purchases that cost more than A$82.50.”
Business.gov.au also notes that if a GST-registered business makes a taxable sale of more than $82.50 including GST, or the customer asks for a tax invoice, the supplier has 28 days to provide one.
What if a supplier does not quote an ABN?
This is where many businesses get caught.
If a supplier does not quote an ABN, and the total payment for goods and services is more than $75 excluding GST, you generally need to withhold tax at the top rate and pay that amount to the ATO.
The current withholding rate is 47%.
Business.gov.au also states: “if you don’t have one, other businesses must withhold 47% tax from any payments they make to you.”
The ATO also warns that if the ABN quoted on the invoice is not valid or the details do not match the supplier, you must withhold from the payment at the top tax rate.
There are exceptions, including where the supplier provides a valid Statement by a supplier not quoting an ABN. If a statement is provided separately, keep it with the transaction records so you can show why you did not withhold.
Do you need to check every supplier every time?
For long-standing suppliers, checking every invoice may not be practical. But supplier details can change. ABNs can be cancelled, GST registrations can end, and business structures can change.
A practical approach is to check:
- all new suppliers before the first payment
- suppliers before claiming GST for the first time
- high-value suppliers before payment
- suppliers with changed bank details
- suppliers with invoices showing GST for the first time
- overseas or online platform suppliers
- contractors included in Taxable Payments Annual Reporting
- your supplier list before BAS lodgment or at least annually
ABN Lookup offers tools for multiple searches using ABNs, ACNs or names, which can be helpful for reviewing a larger supplier list.
Be careful with overseas supplier invoices
Overseas invoices can be tricky.
Australian GST may apply to imported services, digital products and low-value imported goods sold to customers in Australia. However, the rules differ depending on whether the customer is an Australian consumer or a GST-registered Australian business.
The ATO explains that simplified GST registration is available for non-resident businesses that do not need an ABN and sell imported services, digital products or low-value imported goods to Australian consumers.
This means you should not assume that GST shown on an overseas invoice automatically gives your business a GST credit. For GST-registered Australian businesses, it is important to provide your ABN where required and check whether the supply should have GST charged in the first place.
What if you find an error after lodging your BAS?
If you discover that GST was claimed incorrectly, do not simply ignore it and hope it washes through next quarter.
The ATO has rules for correcting GST errors. Some errors can be corrected on a later BAS, but only if the ATO’s conditions are met. The ATO also says you cannot correct an error to claim additional GST credits where the four-year credit time limit has expired.
A good supplier ABN review process helps you catch these issues before BAS lodgment, rather than digging through old transactions later.
Keep digital evidence of your checks
When you check a supplier’s ABN and GST registration, save evidence. This could include a dated PDF extract, screenshot, supplier onboarding checklist or system note attached to the supplier record.
Business.gov.au says businesses can keep digital or paper records, and that the ATO recommends digital record keeping where possible.
Business.gov.au also reminds businesses that records are generally kept for five years.
A dated digital trail is like a gold hallmark: it helps prove the quality of your process if a question is asked later.
ABN Lookup is useful, but it is not a fraud shield
ABN Lookup can help confirm public business details, ABN status, business type and GST registration status. But it does not verify that the bank account on an invoice belongs to that supplier.
Before paying a new supplier, or changing existing supplier bank details, confirm the details using a trusted contact method. Do not rely solely on the email requesting the change.
This is especially important for businesses with high invoice volumes or multiple staff approving supplier payments.
Suggested supplier ABN checklist
Use this checklist before paying a new supplier or claiming GST:
- Search the supplier on ABN Lookup.
- Confirm the ABN is active.
- Confirm the entity name or business name matches the invoice.
- Confirm GST registration applies at the time of supply.
- Check the invoice is a valid tax invoice.
- Check whether the invoice total is over $82.50 including GST.
- For invoices of $1,000 or more, check your business name or ABN appears.
- If no ABN is quoted, consider whether 47% withholding applies.
- If the supplier provides a Statement by a supplier, save it with the transaction.
- Save a dated copy of the ABN Lookup result.
- Confirm supplier bank account changes through a trusted channel.
Why this should be part of your bookkeeping process
The ATO’s latest GST gap estimates show why good GST governance matters. The estimated net GST gap increased to $8.7 billion in 2023–24, or 9.4% of theoretical GST.
For small and medium businesses, this is a reminder that GST compliance is not just an end-of-quarter task. It starts when the invoice arrives.
A strong supplier checking process can help your business:
- reduce incorrect GST claims
- improve BAS accuracy
- avoid no-ABN withholding mistakes
- identify supplier record issues early
- strengthen internal controls
- reduce the risk of invoice fraud
- keep cleaner records for tax time
Need help refining your supplier process?
Supplier ABN checks might not be glamorous, but they are golden when it comes to protecting your business.
At DJ Grigg Financial, we help business owners strengthen their bookkeeping, GST and BAS processes so they can make confident decisions and avoid costly compliance issues.
If you would like help reviewing your supplier list, checking your GST processes or improving your bookkeeping controls, contact DJ Grigg Financial today.