Jotischky joined the company last week as a senior consultant for the agency.
He said: "I'm delighted to have joined PHA Media. The agency has a strong journalistic ethos, which appealed to me, as well as a fresh, dynamic approach to PR and an interesting range of clients.
"As a journalist, I've worked with [PHA Media founder] Phil Hall and his team from the other side of the fence and have always respected him as a first-class operator and a figure of great integrity."
Jotischky ran the business desk for The Daily Telegraph and was previously deputy editor of The Sunday Telegraph for four years.
He has also been the editor of both Metro and the Scottish Daily Mail.
Hall said: "Tim’s breadth of experience is unique in my experience and he will bring so much knowledge, insight and knowhow to our clients."