What Happens If a Subcontractor Doesn’t Have an ABN?

If you hire subcontractors in Australia, the ABN question is not just admin, it is a tax compliance issue. When a subcontractor does not quote an ABN, the payer can be required to withhold tax from the payment and report it to the Australian Taxation Office. The rule exists to reduce tax leakage and push proper reporting, and it shifts risk to the business that pays.

This guide explains what happens when a subcontractor does not have an ABN, when you must withhold, how the 47 percent rule works, the exceptions, and the practical steps to stay compliant. It is written for builders, trades, and small business owners who pay subcontractors and want clear, actionable guidance.

The short answer

If a subcontractor does not quote an ABN and the payment is for work done in the course of an enterprise, you generally must withhold tax at the top marginal rate and send it to the ATO. The current top rate used for no ABN withholding is 47 percent. The subcontractor can later claim the withheld amount as a credit when they lodge their tax return, but the responsibility to withhold sits with the payer.

The core ATO guidance is here:

https://www.ato.gov.au/businesses-and-organisations/hiring-and-paying-your-workers/payg-withholding/payments-you-need-to-withhold-from/withholding-from-suppliers/withholding-if-abn-not-provided
https://www.ato.gov.au/businesses-and-organisations/hiring-and-paying-your-workers/payg-withholding/payments-you-need-to-withhold-from/withholding-from-suppliers/payments-you-don-t-withhold-from

Why the rule exists

The ATO wants income from business activity to be reported correctly. If a supplier or subcontractor does not quote an ABN, the ATO treats it as higher risk and requires the payer to withhold tax. This system is called no ABN withholding and it falls under PAYG withholding rules.

When you must withhold

You generally must withhold when all of the following apply:

You are paying for services or supplies made in the course of the supplier’s enterprise
The supplier does not quote an ABN on the invoice or in writing
No exception applies

In practical terms, if a subcontractor is carrying on a business and has not provided an ABN, you withhold 47 percent from the payment and remit it to the ATO.

When you do not have to withhold

The ATO lists specific exclusions. You do not need to withhold if the subcontractor provides a written statement that one of these applies:

The supply is made as a private or hobby activity, not an enterprise
The supply is wholly input taxed, for example certain financial supplies
The supplier is not required to have an ABN or is not entitled to one
The payment is for goods only and the supplier is not carrying on an enterprise
The supplier is exempt from income tax

If you are unsure, ask the subcontractor to provide the ATO written statement template. Keep it on file.

How the 47 percent withholding works

The withholding is calculated on the gross payment. If the invoice is for 1,000 dollars, you withhold 470 dollars and pay 530 dollars to the subcontractor. The 470 dollars is paid to the ATO and reported as no ABN withholding. The subcontractor can claim the withheld amount as a credit in their tax return.

Key points:

The obligation is on the payer, not the subcontractor
If you fail to withhold when required, the ATO can pursue the payer for the amount
The withholding does not make the subcontractor an employee

What to do before you pay

Use a simple pre payment checklist:

Ask for the ABN and verify it with the Australian Business Register
Confirm the business name on the invoice matches the ABN record
If there is no ABN, ask for a written statement about why they are not quoting one
If no valid statement is provided, withhold at 47 percent

Documenting this step is essential. It shows reasonable care and reduces audit risk.

Reporting and record keeping

If you have withheld because no ABN was quoted, you must report it to the ATO. This is done through your PAYG withholding reporting process and the annual report for no ABN withholding. Your accounting software or BAS agent can help ensure the correct labels are used.

Keep these records:

The invoice or contract
The ABN, if provided
The supplier’s written statement if an exception was claimed
Your calculation of the withholding
Proof of payment to the ATO

Common scenarios in construction

Scenario 1: New subcontractor without an ABN

A new plasterer starts work but does not have an ABN yet. They issue an invoice with a personal name only. In this case you should request the ABN. If they do not provide one and no exception applies, withhold 47 percent.

Scenario 2: Supplier says they are a hobbyist

A carpenter says they do small jobs on the weekend as a hobby. If they provide the ATO written statement that the activity is not an enterprise, you do not have to withhold. Keep the statement on file.

Scenario 3: Mixed supply of goods and services

A supplier provides materials and installation. If they are carrying on an enterprise and do not quote an ABN, you withhold. If it is genuinely a one off private sale of goods, you may not need to withhold, but document why.

What happens to the subcontractor

A subcontractor who does not quote an ABN will receive less cash on the day because of the withholding. They can later claim the withheld amount when they lodge their tax return. If they expect to operate as a business, they should apply for an ABN and update their invoices promptly to avoid the withholding.

Practical tips to avoid payment delays

Include an ABN field in your subcontractor onboarding form
Set your accounting system to block payment without an ABN or a valid statement
Train site admins to request ABNs before the first payment
Keep a register of subcontractor ABNs and review it quarterly

Key gaps we see in practice

During research, several common gaps appeared in top resources and search results:

Many explain the 47 percent rule but do not clarify the exceptions or the need for written statements
Few provide step by step operational checklists tailored for builders and trade contractors
There is limited practical guidance on record keeping and audit readiness
Some articles blur the distinction between employee rules and subcontractor withholding

This article aims to close those gaps by combining the ATO rules with practical workflow guidance.

Conclusion

If a subcontractor does not have an ABN, the payer often must withhold 47 percent and report it to the ATO. The key is to verify ABNs early, request a written statement when an exception is claimed, and document every decision. These steps protect your business and help subcontractors keep their cash flow predictable.

Key takeaways:

No ABN generally means 47 percent withholding and ATO reporting
Exceptions exist, but you need a written statement to rely on them
A simple pre payment checklist prevents compliance mistakes