Sorrels, who most recently worked as a freelance creative and strategic consultant, died suddenly in his sleep in early June. He is survived by his wife Laura and their unborn child.
A memorial service for Sorrels is being held at St Margaret's Church, Westminster on Thursday 6 July.
Friends and former colleagues have paid tribute to Sorrels.
Frank PR co-founder Graham Goodkind, who worked alongside Sorrels between 2009 and 2012, said: "There are only a few people that make an instant and lasting impression on you in life. Jay was one of those people. He touched the lives of so many employees. He made us laugh frequently. He made us think about things completely differently. He taught us new stuff, random stuff, things we never even needed to know about! He was a brilliant colleague and friend to so many people, me included. He was, literally and figuratively, larger than life. A force of nature.
"On behalf of everyone at Frank, my sincerest condolences are with Laura, his unborn daughter, and the rest of the family."
Ogilvy director and former Frank associate director Reema Babakhan described Sorrels as "the man with an extraordinary brain, creative excellence and the kindest of hearts".
"He was an irrepressible whirlwind, dishing out knowledge, enthusiasm and passion - and an endless stream of the world's most weird and wonderful facts. Despite all this, what impacted people the most, was how giving he was of love to those around him. Rest in peace, big man."
Gordon Cherrington, senior creative at Ogilvy, said Sorrels was "a walking, talking Wikipedia with an infectious sense of mischievousness and fun".
"Jay brought a never-ending stream of beautiful insights, brilliant, bold and bizarre ideas and some of the most obscure YouTube videos you could ever wish to see (and sometimes, unsee!). He was a man with the kindest soul and a booming laugh that lit up your life when you needed it most. We all miss him deeply."
Ready10 founder and ex-Frank employee David Fraser said Sorrels was "one of the good guys".
"Kind, considerate, knowledgeable, funny and someone who wanted to brighten up everyone else's day. If we were all more like Jay then the world would be a better place.
"The outpouring of emotion and reflection following Jay's passing from friends and colleagues has been unlike much I have seen before. People who hadn't seen Jay for 10 years have been as touched and shaken as his closest friends, and that probably tells you everything you need to know about him - a unique man who made an impact on everyone and gave so much more than he took. RIP, Jay."