[2] After leaving Holroyd High School in year 11, Regan first worked as a check-out assistant and later a trainee store manager for Kmart Australia.

[2] In 1990, Regan took up as position at the City of Sydney as a clerk in the Engineer's Department, before leaving the council as Street Cleansing and Waste Manager in 2001.

[6] At the 2012 New South Wales local elections, Regan stood again for mayor and C Ward Councillor under the newly renamed "Your Warringah" ticket.

[10] In June 2014, the Independent and Regulatory Pricing Tribunal (IPART) rejected the requested special rate variation of 26.2%, but permitted an increase of 19.7%.

Regan argued that it was intended to be provided for nurses, teachers and police who often had large commuting times to the region as they could not afford to live in the area, and that the social benefits could not be underestimated.

[26][27] In October 2022, Northern Beaches Council was awarded the A. R. Bluett Memorial Award by Local Government NSW, which recognises the best-performing councils in the state in the previous year, with Regan noting: "Since amalgamation we have had a huge focus on repairing and renewing ailing infrastructure, delivering long term financial stability and putting the community at the centre of everything we do.

It hasn’t been easy but this award recognises the hard work and dedication of both the elected Council and our incredible staff to deliver great outcomes for our community."

The chair of the award trustees, Les McMahon, also noted that the Council had "led its community through a number of challenges including the ongoing COVID-19 pandemic and unprecedented wet weather events.

[30][31][32] Regan noted that the decision of the NSW Government-appointed planning panel to approve a planning proposal for a large 450-dwelling residential subdivision in an area of native bushland known as "Lizard Rock" in Belrose, despite the loss of native bushland and housing development in a bushfire-prone area that it represented, encouraged him to stand on a platform that included advocating for sustainable development.

[2] As an elected member of parliament, Regan is permitted to retain his offices as mayor and councillor of Northern Beaches Council "for the balance of the person’s term of office as a councillor or for the period of 2 years (whichever is the shorter period)" in accordance with Section 275(5) of the Local Government Act, 1993, a requirement which came into effect following the passage of the Local Government Amendment (Members of Parliament) Act, 2012.