Senior AP Specialist

Security Equipment Supply Inc•Earth City, MO

8d•Hybrid

About The Position

Security Equipment Supply (SES) is seeking a Senior AP Specialist to take full ownership of a vendor portfolio and the complete non-PO invoice lifecycle. This role involves managing vendor relationships, processing various types of invoices, identifying potential Use Tax exposure, and ensuring the company's cash is protected by catching discrepancies before they become significant issues. The ideal candidate is independent, uses sound judgment within policy, and acts as a line of defense for the company's finances.

Requirements

High school diploma or equivalent
ERP experience required
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

Nice To Haves

Coursework in accounting or business a plus
Microsoft Dynamics 365 Finance & Supply Chain preferred

Responsibilities

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