On Monday, the tech group confirmed that Mr Blomfield, who joined Iress in October last year, is leaving effective immediately for health reasons.
“My time at Iress has been one of the highlights of my career,” Mr Blomfield said.
“I am disappointed to have to step away from a great company with a clear strategy to deliver it. I am confident I will regain my health, but for now my decision to resign is the right one for me and my family.”
Mr Blomfield will be replaced by chief client solutions officer, Simon New, who first joined Iress in 2015 as group executive of strategy.
Meanwhile Mr Lill will depart Iress after 5 years in the chief communications and marketing officer role to spend an “extended period of time” with family overseas.
Current head of communications, Kelly Fisk, will step in Mr Lill’s position until a permanent appointment is made.
Mr Lill will continue with the company until at least the end of 2021.
Iress chief executive Andrew Walsh thanked Mr Blomfield and Mr Lill for their efforts, including their leadership throughout the COVID-19 pandemic.
“While it is always sad to lose high-quality colleagues who have contributed to the successes of Iress, I am extremely confident in the strength and depth of our team and our succession pipeline,” Mr Walsh said.
“As a business we remain focused on executing our strategy to continue to make good progress towards our 2025 targets.”