Administrative Assistant

DU Family of Companies is a network of fire protection, life safety, and security service companies, protecting people and property across 35+ branches in 11 states. Founded in 1994,
One Source Security
, headquartered in Merrimack, NH, is a full-service security provider specializing in commercial and residential security systems, access control, video surveillance, locksmith services, and customized integrated solutions. With more than three decades of experience, the company assesses security risks, designs tailored systems, and provides 24/7 support to help keep homes and businesses protected. Living our motto, ‘we protect what you value most,’ One Source Security offers a challenging and rewarding work environment for those passionate about keeping communities safe.

Due to continued growth, we are looking to add an Administrative Assistant to our Merrimack, NH team. This role provides administrative support across the branch while assisting with collections, accounts receivable, payroll time entry, scheduling, and general office operations. Success in this role requires strong organizational skills, attention to detail, professional communication, discretion, and the ability to manage multiple priorities in a fast-paced environment.

• Provide general administrative support to branch employees and management.
• Answer phones, greet visitors, and handle incoming and outgoing correspondence.
• Maintain accurate files, records, and supporting documentation.
• Assist with data entry, scheduling, and other clerical responsibilities.
• Order and manage office supplies and coordinate with vendors as needed.
• Monitor customer accounts and follow up on outstanding balances.
• Contact customers regarding past-due invoices and document collection efforts.
• Assist with resolving billing discrepancies and applying customer payments.
• Support accounts receivable reporting and month-end processes.
• Collect, review, and enter employee time into the payroll system.
• Verify the accuracy of employee hours, job codes, and required approvals.
• Coordinate with supervisors to resolve time-entry discrepancies.
• Protect confidential employee, customer, and company information.
• Perform other administrative duties and special projects as assigned.

• High school diploma or equivalent.
• At least two years of administrative, accounts receivable, or related office experience.
• Proficiency with Microsoft Office, including Word, Excel, and Outlook.
• Strong organizational, communication, and time-management skills.
• Strong attention to detail and commitment to accuracy.
• Ability to manage multiple priorities in a fast-paced environment.
• Ability to communicate professionally with customers, vendors, employees, and management.
• Ability to handle confidential information with discretion.
• Ability to work independently and as part of a team.

• Experience in the security, construction, fire protection, or a related industry.
• Familiarity with collections and accounts receivable processes.
• Experience with payroll time-entry or timekeeping systems.

• Work primarily in a standard office environment.
• Sit and use a computer for extended periods.
• Regularly use hands and fingers to operate a computer, telephone, and standard office equipment.
• Occasionally stand, walk, bend, and reach to access files, supplies, and office equipment.
• Occasionally lift and carry office supplies or related materials weighing up to 15 pounds.

The wage for this role is $20 to $25 per hour
, based on experience and qualifications.

As part of the DU Family of Companies, we believe that empowering and investing in our employees as leaders develops an organization that delivers innovative solutions and services that create a superior customer experience. The unique blend of our leader's abilities and the ownership of their work, combined with our culture and values, creates something that is simply described as the Davis-Ulmer difference.

• Competitive Compensation - We offer a competitive wage based on your experience and qualifications.
• Comprehensive Benefits Package - Receive medical, dental, and vision insurance, a 401(k) with company match, and paid time off.
• Strength of the Family - As part of the DU Family of Companies, you gain the stability and resources of a growing network of industry-leading companies.
• Backed by APi Group - Benefit from the support and opportunity that come with being part of a global leader in…