Payment of finder's fees to 3rd parties Tax Deductable for Sole Traders?

As a Marketing Consultant who is a sole trader I sometimes get my contracts through a middle man.

This middle man looks for and introduces me to prospective clients.

As a compensation for the service of finding / introducing me to a client, I need to pay this middle man a finder's fee/Commission.

This fee is roughly 15% of the value of the contract that I obtain with the client.

As this is a purely business-related cost, I was wondering if I can deduct these cost as a business expense?

Thanks in advance for helping me find an answer to tis question.

Rick