Payroll software systems that fail to keep up with more flexible work conditions are exposing Australian companies to risks of huge fines that will only get bigger when new right to disconnect laws and other regulatory changes come into effect, a workplace management expert has warned.

Michael Clark, a former Fair Work Ombudsman executive who now operates the workforce management specialist CXTT Consulting, said many payroll software systems fail to keep track of simple things like when remote workers log into and out of their workplace apps, and that companies could be facing a huge bill from the ombudsman when its fines increase next year.