The funds were provided by equity fund BGF.
This marks the second investment from BGF into the company. Action24 previously received a €3.6m investment from BGF in 2020, with the investor acquiring a significant minority stake at the time.
Action24 provides monitored intruder alarm systems, CCTV and access control solutions to more than 20,000 residential and commercial customers.
The business, which was founded in 1981, employs 87 people at its facility in Sandyford.
Customer numbers have surged by 50pc since the first investment from BGF almost four years ago, according to Action24. At the time, the business had around 13,000 companies.
Following the initial investment, it has also acquired a number of companies, including Integral Security Limited and Wilson Security Systems.
Last year, the business also completed the acquisition of the security customer book of Smartzone which went into receivership.
“BGF has been a wonderful supporter of the business and they have provided us with the firepower which has enabled us to execute on our ambition,” Action24 chief executive Aaron Mooney said.
“We believe there are significant opportunities to grow further in a consolidating market before we begin to explore potential opportunities in other markets,” he added.
Action24 reported that Gene Browne, founder of City Bin Company, will also join the company’s board as a non-executive director. Mr Browne led the City Bin Company for 25 years before the company’s sale to Thorntons Recycling in 2023.
BGF was set up in Ireland in 2017 and is supported by the Ireland Strategic Investment Fund, as well as AIB and Bank of Ireland. The fund makes equity investments of between €1m and €10m in Irish companies, with further funding available in subsequent rounds.
It only takes minority positions in businesses and made two investments into Irish companies last year.
This included the Avoca Clinic, an Irish cosmetic surgery practice. It received a €7m investment from the fund last September. This was the third investment by BGF into a female-led Irish business.
The Avoca Clinic, which was founded in 2012, has three clinics in Wicklow, Limerick and Dundalk.
BGF also announced a multimillion euro investment into marine plant hire business Ocean Crest Marine last September. Founded in 2012, the Galway company employs 10 people.