Senior AP Specialist

SES - Security Equipment Supply; Earth City (MO); Hybrid; USD 65,000 - 85,000; Full time

Benefits offered by this job

Profit sharing

SEP IRA contributions

Health benefits

Hybrid work schedule

Job summary

Security Equipment Supply, Inc. (SES) is seeking a Senior AP Specialist in Earth City, MO. You will own the entire vendor portfolio, manage the complete non-PO invoice lifecycle, and act as a line of defense for cash quality. This role requires independent judgment and strong vendor relations.

You’ll manage PO and non-PO invoices, ensure accurate coding, and uphold policy-driven processes while collaborating with teams during monthly close and audits.

Qualifications

• 5+ years of AP experience with full invoice-cycle ownership.
• Track record of independent vendor communication and discrepancy resolution.
• Knowledge of Use Tax concepts or ability to learn quickly.
• Strong Excel skills.

Responsibilities

• Own your own vendor book as the single point of contact for inquiries and discrepancies.
• Process PO invoices with automated 3-way match.
• Process all non-PO invoices (costs like professional services, utilities, operational vendors, subscriptions).
• Flag non-PO invoices for potential Use Tax exposure during processing.
• Validate, code, and resolve invoice issues.
• Handle vendor onboarding documentation and setup/change requests per policy.
• Prepare payment batches and maintain audit-ready documentation and approval trails.

Skills

AP experience

Vendor communication

Use Tax concepts

Excel skills

Education

High School Diploma or equivalent

Accounting coursework

Tools

Microsoft Dynamics 365 Finance & Supply Chain

Job description

Security Equipment Supply, Inc. (SES)

Job Title

Senior AP Specialist

Company

Security Equipment Supply, Inc. (SES)

Location

Earth City, MO

Job Type

Full-Time | Non-Exempt (Hourly) | 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 16 locations across 11 states, delivering trusted solutions in access control, fire and life safety, surveillance, home entertainment, and more.

We're in a transformative phase—modernizing 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 don't just work here — we care for what we've 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

Security Equipment Supply is looking for a Senior AP Specialist who wants full ownership of a desk — not a seat processing someone else's workload.

Yes, invoices need to be processed and vendors need to be paid. But this is not a role where you wait to be handed a stack and told what to do with it. You'll own the complete vendor relationship and the full non-PO invoice lifecycle for the entire portfolio, working independently and using sound judgment within policy. Just as important, you'll be a line of defense for the company's cash — someone who catches what's off before it becomes a real problem, not just someone who processes what's in front of them.

What You'll Do

• Own your own vendor book as the single point of contact for inquiries and discrepancies
• Process PO invoices, supported by an automated 3-way match
• Process all non-PO (“cost”) invoices — professional services, utilities, operational vendors, subscriptions, and anything without a PO
• Flag non-PO invoices for potential Use Tax exposure during processing
• Validate, code, and resolve invoice issues
• Handle vendor onboarding documentation and setup/change requests per policy
• Prepare payment batches and maintain audit-ready documentation and approval trails

Who You Are

If you're the kind of AP Specialist who runs your own desk, resolves problems before they're escalated to you, and doesn't need constant direction to keep a full vendor portfolio moving, we'd like to talk with you. You take ownership seriously — questioning something that looks off rather than waving it through just to clear your queue.

What We're Looking For

Education

High school diploma or equivalent; coursework in accounting or business a plus

Training & Certifications

ERP experience required; Microsoft Dynamics 365 Finance & Supply Chain preferred

Work Experience

• 5+ years of AP experience with full invoice-cycle ownership
• Track record of independent vendor communication and discrepancy resolution
• Working knowledge of Use Tax concepts, or ability to learn quickly
• Strong Excel skills

How We Measure Success

• Invoice processing accuracy and timeliness
• Vendor relationship quality and response time
• Documentation completeness and audit readiness
• Catching and flagging issues before they become payment or compliance problems
• Smooth handoff of approval routing as automated workflows come online

Why Join SES?

You’ll have real ownership of your portfolio within a framework of clear policy and accountability. You’ll be part of a team that values independence, expects accuracy, and respects people who can run their own desk with confidence.

• 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
• Hybrid flexibility: 3 days in-office, 2 days remote per week after an initial training period

Work Environment and Physical Demands

• Standard office setting
• Ability to lift up to 25 lbs occasionally
• Occasional evening/weekend work during month-end close

Ready to Own the Desk?

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