Haissene Costa
Luanda,Angola
Summary
Detail-oriented finance and billing professional with over 17 years of experience managing high-volume accounts receivable portfolios in structured oil and gas environments. Expertise in SAP and Primavera, combined with a strong understanding of regulatory compliance, financial reconciliation, and audit support, ensures meticulous oversight and accuracy. Proven success in enhancing cash flow performance and reinforcing internal controls demonstrates a commitment to operational excellence. A results-driven approach fosters collaboration and cultivates client satisfaction, particularly in addressing past-due accounts and achieving team objectives.
Overview
18
18
years of professional experience
Work History
Senior Accounts Receivable & Billing Technician
SONILS, Lda
Luanda, Angola
01.2011 - Current
- Senior finance professional responsible for governance, optimization and control of high-volume billing and accounts receivable operations within structured Oil & Gas environments.
- Govern annual accounts receivable portfolio representing multi-million USD equivalent revenue streams across the full SONILS customer base.
- Lead end-to-end billing cycle, processing and validating 500–800+ invoices per month across multiple operational contracts.
- Reduced aged receivables (>90 days) by 18–22% through structured recovery frameworks, strengthened monitoring and disciplined follow-up controls.
- Improved billing accuracy from approximately 90% to consistently above 99% by enhancing validation, reconciliation and verification procedures.
- Partner with Finance, Commercial and Operations teams to optimize DSO, accelerate cash collection and improve cash-flow performance.
- Implemented aging analysis dashboards and performance tracking tools, increasing management visibility and supporting strategic decision-making.
- Strengthened revenue protection and internal control protocols, minimizing exposure to contractual, fiscal and operational risks.
- Review, validate and process claims, ensuring compliance with contractual terms and Angola Oil & Gas fiscal and regulatory standards.
- Reconcile discrepancies between paper-based and electronic invoices, ensuring data integrity and audit readiness.
- Support internal and external audits with zero major compliance findings, maintaining robust documentation and governance standards.
- Communicate with clients to resolve billing issues and provide effective support, reinforcing professional relationships.
- Train and mentor new team members on ERP systems (SAP SD / Primavera), company policies and financial control procedures.
- Continuously assess and improve billing processes to enhance operational efficiency and governance integrity.
Commercial Assistant
UNITEL
Luanda, Angola
01.2008 - 01.2011
- Supported revenue growth initiatives within high-volume telecommunications environment.
- Improved commercial reporting accuracy and documentation controls.
- Coordinated cross-department client communication enhancing operational efficiency.
Education
Academic Studies - Law
Universidade Lusíada de Angola
Skills
Strategic Accounts Receivable Leadership
Multi-Million USD Revenue Portfolio Governance
Oil & Gas Contract Billing & Compliance Management
SAP SD & Primavera ERP Optimization
DSO Reduction & Cash Flow Acceleration
Audit-Ready Internal Control Frameworks
KPI Development & Performance Monitoring
Cross-Functional Stakeholder Alignment
Invoice Delivery & Billing Reconciliation Specialist
Languages
Portuguese
Native or Bilingual
English
Full Professional
Certifications & Training
- SAP Portugal – Billing & Pricing (SCM615, SCM620)
- EY – Forecast & Budget Management
- PwC – Tax Compliance & Fiscal Governance
- IEFE – Billing Standards & Financial Excel
- IFBA – Banking Operations
- ESSA – Sonangol Basic Safety Training
Timeline
Senior Accounts Receivable & Billing Technician
SONILS, Lda
01.2011 - Current
Commercial Assistant
UNITEL
01.2008 - 01.2011
Academic Studies - Law
Universidade Lusíada de Angola