Accounts Receivable Specialist

507 Witt O'Brien's, LLC; Houston (TX); On-site; USD 36,000 - 47,000; Full time

Job summary

Ambipar is seeking an Accounts Receivable Specialist to join our Finance/Accounting team in Houston, TX. This role manages invoicing, cash application, reconciliations and collections, ensuring accurate customer billing and timely payments.

Ideal candidates have 3–5 years in AR, work well independently and with cross-functional teams, and are proficient in Workday and Excel. Responsibility includes month-end close support and AR reporting.

Qualifications

• 3–5 years of accounts receivable, billing or related accounting experience.
• Degree in accounting, finance, or business preferred.
• Strong understanding of AR principles and general accounting.
• Experience with Workday ERP system.
• Proficient Excel skills (formulas, filtering, sorting).
• Excellent attention to detail and communication.
• Ability to manage multiple tasks in a fast-paced environment.

Responsibilities

• Manage day-to-day accounts receivable processes including invoicing, cash application, reconciliations, and collections.
• Prepare, review, and distribute invoices and credit memos.
• Apply customer payments accurately and timely.
• Monitor aging reports and follow up on past-due balances.
• Communicate with customers on invoices and discrepancies.
• Resolve billing discrepancies and variances.
• Assist month-end close activities and AR reporting.
• Maintain AR reports and aging schedules.
• Support audits related to AR.
• Identify and escalate potential credit issues.

Skills

Accounts Receivable

Billing

Cash Application

Reconciliations

Excel

Communication

Education

Associate or Bachelor's degree in accounting/finance

Tools

Workday

Job description

Are you looking for an opportunity to truly make a difference? Do you want to join a collaborative, mission-driven team that protects the planet, strengthens communities, and supports businesses when they need it most? Are you seeking a place where your work contributes directly to an organization known for excellence in environmental services, crisis management, and emergency response? If your answer is “yes,” then you belong at Ambipar.

Accounts Receivable Specialist Position Summary

Ambipar / Witt O’Brien’s is seeking a detail-oriented and experienced Accounts Receivable Specialist to join our Finance/Accounting team. This position is responsible for managing the accounts receivable cycle, ensuring timely and accurate customer invoicing, payment application, account reconciliation, collections, and resolution of outstanding balances. The ideal candidate has strong accounting fundamentals, excellent attention to detail, effective communication skills, and the ability to independently manage a portfolio of customer accounts while working collaboratively with internal teams.

Position Details

• Reports to: AR/AP Manager
• Location: Houston, TX
• Position Type: Regular Full-Time
• FLSA Status: Non-Exempt
• Pay: Hourly
• Compensation: $26 - $34/hour
• Travel: <5%

Essential Job Functions

• Manage the day-to-day accounts receivable process, including invoicing, cash application, account reconciliation, and collections.
• Prepare, review, and distribute accurate customer invoices and credit memos.
• Apply customer payments accurately and timely to the appropriate accounts.
• Monitor accounts receivable aging reports and proactively follow up on past-due balances.
• Communicate professionally with customers regarding outstanding invoices, payment status, discrepancies, and account questions.
• Research and resolve billing discrepancies, short payments, unapplied cash, and account variances.
• Reconcile customer accounts and maintain accurate supporting documentation.
• Work closely with business unit and other stakeholders to resolve billing and payment issues.
• Assist with month-end and year-end close activities, including AR reconciliations and reporting.
• Prepare and maintain accounts receivable reports, aging schedules, and collection summaries.
• Identify potential credit and collection issues and escalate concerns when appropriate.
• Maintain accurate customer account records in Workday.
• Support internal and external audit requests related to accounts receivable.
• Recommend and implement process improvements to increase efficiency, accuracy, and timely collections.
• Perform other accounting and finance duties as assigned.

Minimum Job Requirements

• 3–5 years of accounts receivable, billing, collections, or related accounting experience.
• Associate or bachelor's degree in accounting, finance, business, or a related field preferred.
• Strong understanding of accounts receivable and general accounting principles.
• Experience with Workday as an ERP system.
• Strong Microsoft Excel skills, including experience with formulas, filtering, sorting, and reconciliation.
• Excellent attention to detail and organizational skills.
• Strong analytical and problem-solving abilities.
• Effective written and verbal communication skills.
• Ability to prioritize multiple tasks and meet deadlines in a fast-paced environment.
• Ability to work independently while also collaborating effectively with cross-functional teams.
• Demonstrated ability to handle sensitive financial information with discretion.

Preferred Job Requirements

• Experience managing a high-volume accounts receivable portfolio.
• Experience with B2B collections and customer account management.
• Familiarity with cash application, credit memos, deductions, and unapplied cash.
• Experience with month-end close and account reconciliations.
• Experience creating and analyzing AR aging and collections reports.
• Intermediate to advanced Excel skills, including PivotTables and lookup functions.

Work Schedule/Work Environment

This is an in-office position. The employee is expected to work on-site at the company’s designated workplace during regular business hours and maintain a professional, collaborative work environment. The role involves regular interaction with colleagues, management, clients, customers, and/or other stakeholders, as applicable. The position may require extended periods of sitting and working at a computer, as well as occasional movement throughout the workplace and attendance at in-person meetings or events. Remote work may also be authorized on a case-by-case basis.

Job Description and Hiring Disclaimer

This position description incorporates the core responsibilities of the job. It recognizes that other related duties not specifically mentioned might also be performed, and that not all responsibilities may be carried out depending on operational needs. The hiring department will conduct interviews of qualified individuals prior to requesting a criminal background check, and no job application submitted prior to such interview shall inquire into an applicant’s criminal history. If this position is subject to a background check for any convictions related to its responsibilities and requirements, employment will be contingent upon successful completion of a background investigation including criminal history. Criminal history will not automatically disqualify a candidate. Employment will also be contingent upon successful completion of a drug test.

Commitment to Diversity

Ambipar / Witt O’Brien’s is always looking for the most qualified and experienced professionals with a passion for public safety, emergency management, homeland security, disaster response, and continuity of operations. We are an equal opportunity employer, and all qualified applicants will receive consideration for employment without regard to race, color, religion, sex, national origin, disability status, protected veteran status, or any other characteristic protected by law.

About Ambipar

Ambipar is a global leader in environmental and emergency management solutions. In the United States, our diverse portfolio spans emergency consulting and risk mitigation, grants management support, 24/7 emergency response, environmental remediation, industrial services, business continuity, and disaster recovery. Through our Witt O'Brien's consulting business, we help communities build resilience in a rapidly changing world—advising clients on how to mitigate risk, prepare for crises, respond effectively, and recover stronger. Across the country, our emergency response teams manage environmental incidents of all types—from chemical and hazardous waste spills to silo fire suppression and industrial vacuum services. We also deliver specialized training programs that equip emergency responders with the skills they need to act swiftly and safely. As the frequency and complexity of both natural and human-made disasters continue to grow, the need for our expertise has never been greater. We invite you to join an ambitious, forward-thinking team of top professionals who are committed to safeguarding people, communities, and the environment. Together, we can take our organization—and your career—to the next level.