Accounting Operations Specialist - AP/AR & Treasury

Mainstay Labs Inc.; Northern (KY); Hybrid; USD 52,000 - 68,000; Full time

Job summary

Mainstay is hiring an Accounting Operations Associate to support the finance and accounting team as we scale. You’ll oversee accounts payable and accounts receivable, daily treasury functions, and ensure GL data integrity across systems.

This role emphasizes building solid financial processes at a fast-growing startup. Responsibilities include vendor onboarding, invoicing, cash management, month-end close, and supporting FP&A.

Qualifications

• 1–3 years in accounting or related finance role with meaningful AP/AR experience.
• Exposure to treasury or cash management tasks is a strong plus.
• Experience administering financial systems or banking portals.
• Strong Excel/spreadsheet skills across multiple financial systems.
• Detail-oriented with deadline-driven, controls-sensitive work.

Responsibilities

• Own the full AP cycle: process vendor invoices, verify coding and approvals, manage payment runs.
• Own the full AR cycle: generate and send invoices, track collections, handle past-due follow-up.
• Maintain AP/AR aging, flag risks, and resolve discrepancies with vendors and customers.
• Track AP/AR KPIs (DPO, DSO) and drive process improvements.
• Vendor onboarding and record maintenance; respond to AP/AR questions.
• Monitor daily cash positions and process wire transfers/ACH payments.
• Support treasury cash flow forecasting and reconcile accounts.
• Own ownership of ERP/AP/AR/banking platforms and integrations.
• Prepare journal entries and support month-end close; reconcile accounts.
• Assist in monthly financial reporting and variance analysis.
• Support budget-to-actual tracking and ad hoc data requests.

Skills

AP/AR experience

Excel proficiency

Financial systems mastery

Attention to detail

Vendor communication

Education

Accounting/Finance degree preferred

Tools

ERP system

Bill.com

Banking portals

Job description

Mainstay is hiring an Accounting Operations Associate to support the finance and accounting team as we scale. You’ll oversee accounts payable and accounts receivable, daily treasury functions, and ensure GL data integrity across systems.

This role emphasizes building solid financial processes at a fast-growing startup. Responsibilities include vendor onboarding, invoicing, cash management, month-end close, and supporting FP&A.