Most guides to buying a bus start with the bus. That is the wrong end. Here is roughly the order things actually need to happen.

Accreditation first

Operator accreditation is a state matter and the requirements differ. It generally covers maintenance systems, driver management, and demonstrating you can run safely. It takes time, and it is required before you carry a paying passenger.

Start this before you buy anything. People who buy the bus first spend the waiting period paying for an asset that cannot work.

Then work out what the job actually needs

How many passengers, how far, how often, what terrain, and what the contract requires. Write it down before you look at vehicles, because it is very easy to be talked into more bus than the job needs.

A 57-seat coach on a run that never carries more than twenty is expensive to buy, expensive to fuel and harder to park.

Insurance before finance

Get an indicative quote early. Premiums vary enormously with vehicle type, passenger numbers, use and your own history. It is a real operating cost and it occasionally changes which vehicle makes sense.

Finance

Most operators finance. Talk to a broker or your bank early, because approval takes longer than people expect and the terms affect what you can afford.

A supplier who tells you they can arrange your credit should be asked whether they are licensed to do so. Arranging credit is regulated work.

Then, finally, the vehicle

New or used, and both are defensible. A used bus conserves capital and gets you earning sooner. A new bus comes with warranty, current emissions compliance and a known history.

Whichever you choose, ask about parts and service before you ask about price. The purchase is one day; the relationship is ten years.

And build a maintenance plan before the first service is due

Not when it is due. Accreditation requires a maintenance system, your insurer will ask about it, and an unplanned failure on a contract run is the fastest way to lose the contract.