Vehicle trade plates - An allowable expense?

I assess, test drive and move vehicles (self employed, casual, part-time). Work availability varies but could be increased by having trade plates. Would the annual cost of purchasing trade plates be an allowable expense? If I didn't get any extra jobs by having the plates could I still claim the expense as a loss?

Hi

The purchase of trade plates can be claimed as a business expense, as a vehicle licence fee.  
Have a look at Expenses if you're self-employed and Trade licence plates.

Thank you

Thank you for your clear reply in line one.