This is a pretty general question with lots of potential responses.
Is there any further information you can provide to help us understand your situation?
- What type of service will you be providing?
- If it isn't an option to take payment in advance of providing the service, could you at least take a deposit?
- Is it an option to request credit card details in advance of performing the service, on agreement that their card will be charged once the services are complete?
You should be able to cover a large part of your exposure by drafting some terms and conditions the customer must acknowledge before requesting the service. No matter how you look at it though, if you are performing a service before getting paid then you are at risk and would have to resort to pursuing someone for breach of contract if they refused to pay.
Do you mean in terms of having someone draft up terms and conditions for you? That depends on your budget. Ideally, you should get a lawyer to put together some T&Cs based on your specific business. But if budget doesn't allow, you could always look for some template T&Cs on the internet and do some research.
Yes as per the others' comments above, a lawyer is obviously be bound by obligations of confidentiality so you would be able to explain your business idea in detail to them and get customised advice on all aspects of your business without worrying about your idea being exploited by someone else.
Alternatively, if you simply can't afford that, there are some online legal document resources where you can buy customisable template terms and conditions who will be able to provide a customised agreement for you at a reduced rate.
If you are dealing in money then you will need an Australian Financial Services Licence
(indeed I cannot imagine circumstances where you could operate lawfully
in this field in Australia without one).
If you can't get one, then your model (whatever it is), is probably not lawful.
And I agree with the above comments - you need formal legal advice.
This is especially the case if you think you are... being innovative*...
in the field of money.