Three Reference Letters

Hi,

I work for a leading manufacturer in its Industry. I have two direct reporting bosses, i.e. CFO and MD. So my two reference letters are pretty much set. What about the third?

I casually asked a client of our company and he is more than happy to provide reference letter. I am his only point of contact for the company so all the dealings with him is done by me. Will this make any sense?

Thanks