Is it rude to ask for a licence number?

No. It is routine, and licensed tradespeople are asked constantly. Many states require the licence number to appear on quotes and advertising anyway, so you are often asking for something that should already have been provided.

What if they won't answer some of these?

Distinguish between cannot and will not. Not knowing a certificate expiry off the top of their head is normal; declining to name the contracting entity or refusing to confirm a licence is not. The second kind of reluctance is the answer to your question.

Do I need all of this for a small job?

No. Scale it to the risk. For a two-hour job the licence question and a written price are enough. The full list is for work where the worst realistic outcome is expensive — anything involving water, gas, electricity, heights or structure.

Questions to ask before work starts

Short answer

Establish who you are contracting with and their ABN, whether they hold the licence for this work, whether they carry public liability insurance, whether the price is fixed or an estimate, what is excluded, how variations will be handled, who is physically doing the work, what happens to your deposit, when it starts and finishes, and what paperwork you receive at the end.

None of this is confrontational. An established business is asked these constantly and answers without friction, which is itself the most useful thing the exercise tells you.

Who you are dealing with

What is the legal entity I am contracting with, and its ABN?
What is your licence number for this work, and which state issued it?
Do you carry public liability insurance, and can I see the certificate of currency?
Will your own people do the work, or is any of it subcontracted? If so, who?

Money

Is this a fixed quote or an estimate?
What is excluded — rubbish removal, making good, scaffolding, permits?
If something unexpected is found, how is it handled and who authorises the cost?
What deposit do you need, and what does it cover?

Time and paperwork

When will it start, how long will it take, and what would delay it?
What do I receive at the end — invoice, compliance certificate, warranty, manuals?

How to read the answers

The content matters less than the manner. A tradesperson who answers the licence question immediately, says plainly what is excluded, and volunteers where the price could move is telling you how the job will be run. Vagueness about the entity, reluctance about insurance, or irritation at being asked at all are all information, and they are cheaper to collect now than to discover later.

For context on why these are worth asking: 90.2% of the 36,230 businesses measured here publish no ABN a customer can find, and 4.8% list a phone number that contradicts their own website. The baseline is not as solid as most people assume.

Common questions

Is it rude to ask for a licence number?: No. It is routine, and licensed tradespeople are asked constantly. Many states require the licence number to appear on quotes and advertising anyway, so you are often asking for something that should already have been provided.
What if they won't answer some of these?: Distinguish between cannot and will not. Not knowing a certificate expiry off the top of their head is normal; declining to name the contracting entity or refusing to confirm a licence is not. The second kind of reluctance is the answer to your question.
Do I need all of this for a small job?: No. Scale it to the risk. For a two-hour job the licence question and a written price are enough. The full list is for work where the worst realistic outcome is expensive — anything involving water, gas, electricity, heights or structure.

The questions to ask before work starts