Senior AP Specialist

Senior AP Specialist

Company: Security Equipment Supply, Inc. (SES)

Location: Earth City, MO

Job Type: Full-Time | Non-Exempt | Hybrid Work Model

About Security Equipment Supply (SES)

Security Equipment Supply (SES) is a second-generation, family-owned distributor of low-voltage electronics. Since 1982, we've grown to 15 locations across 12 states, delivering trusted solutions in access control, fire and life safety, surveillance, home entertainment, and more.

Were in a transformative phasemodernizing operations, investing in technology, and enhancing customer and employee experiences. SES is committed to growing talent from within and creating meaningful career paths across the organization. Most roles are hybrid, providing flexibility while driving impact.

At SES, we dont just work here we care for what weve built and the people we work with.

Live the SES Way: Family Respect Celebration Excellence Integrity

Work the SES Way: Curiosity Fun-Loving Spirit Commitment to Growth

About the Role

Are you an experienced AP professional who can spot a problem before anyone brings it to your attention? Someone who knows that even with automation in place, exceptions happen, vendors have questions, and unexpected issues need to be resolved quickly?

Were looking for someone who thinks beyond the invoice.

Security Equipment Supply (SES) is looking for a Senior AP Specialist who is sharp, self-directed, detail-oriented, and able to adapt when the day doesnt go as planned. The routine work matters, but the real value you bring is knowing what to look for, recognizing when something isnt right, and figuring out what needs to happen next.

This is not a role for someone who simply works through a queue of transactions or waits to be told what needs attention. Youll manage your own vendor portfolio, resolve discrepancies, respond to unexpected issues, and help protect company cash by catching errors and potential compliance concerns before they become bigger problems.

If youre someone who sees what needs to be done, takes action, and keeps things moving without constant direction, wed like to meet you.

What Youll Do

• Own your vendor portfolio. Serve as the primary point of contact for vendor questions, invoice discrepancies, payment concerns, and account resolution.
• Manage the full invoice lifecycle. Process PO invoices through automated three-way matching and independently manage non-PO invoices, including professional services, utilities, subscriptions, and operational expenses.
• Catch what others might miss. Identify discrepancies, unusual charges, coding errors, duplicate invoices, and potential Use Tax exposure before they create financial or compliance issues.
• Solve problems as they arise. Investigate exceptions, determine the root cause, coordinate with internal teams and vendors, and drive issues toward resolution.
• Move quickly when priorities change. Respond to urgent payment issues, unexpected invoice problems, and time-sensitive requests without losing sight of accuracy and deadlines.
• Protect the integrity of the process. Maintain accurate documentation, approval trails, vendor records, and audit-ready files.
• Manage vendor changes and payments. Handle onboarding documentation, vendor setup and change requests, and payment batch preparation in accordance with company policies.
• Adapt as technology evolves. Work effectively within automated workflows, identify exceptions that require human judgment, and help ensure approvals and processes continue moving smoothly.

Qualifications

• 5+ years of accounts payable experience, including full invoice-cycle responsibility.
• Proven experience independently managing vendor relationships and resolving invoice discrepancies.
• ERP experience required; Microsoft Dynamics 365 Finance & Supply Chain is preferred.
• Strong Excel skills and comfort working with financial data.
• Working knowledge of Use Tax concepts or the ability to learn and apply them quickly.
• A track record of accuracy, follow-through, independent problem-solving, and managing competing priorities.
• High school diploma or equivalent; accounting or business coursework is a plus.

Success Metrics

• Youre proactive. You notice when something is missing, incorrect, unusual, or falling behind without needing someone to point it out.
• Youre a problem solver. When an invoice doesnt match, a vendor raises an issue, or an urgent payment problem surfaces, you investigate and find a solution rather than simply passing it along.
• Youre nimble. You understand that priorities can change quickly. You can pivot when an emergency arises, make sound decisions, and keep other work moving.
• Youre self-directed. You manage your workload, follow through on commitments, and know when to act independently and when to escalate an issue.
• You have exceptional attention to detail. You recognize that small mistakes can create significant financial, operational, and compliance problems.
• You bring a sense of urgency. You respond promptly, prioritize appropriately, and understand the importance of keeping vendors paid and issues resolved.
• You exercise sound judgment. You know when something doesnt look right, ask the right questions, and never push something through just to clear your queue.
• You communicate confidently. You can work directly with vendors and internal stakeholders to resolve difficult or time-sensitive situations professionally.

Work Environment and Physical Requirements

This position is primarily performed in a professional office environment and requires regular use of a computer, telephone, and other standard office technology. The employee must be able to remain in a stationary position for extended periods, occasionally move throughout the workplace, and communicate effectively with colleagues, customers, and business partners. The employee may occasionally move office materials weighing up to 15 pounds. Occasional evening/weekend hours during month-end close.

Why Join SES?

Competitive compensation: market-aligned salary + performance incentives

Profit sharing & retirement: SEP IRA contributions and annual profit-sharing bonuses

Health benefits: affordable medical, dental, and vision plans

Career growth: ongoing development, advancement opportunities, and a promote- from-within culture

Next Steps

As part of our hiring process, we invite you to complete a brief personality survey to help us understand how you work best.

Be part of a growing company where your work matters, your growth is supported, and your success is celebrated.