**Requirements:** * Technical or university studies in Administration, Accounting, Finance, or related fields. * Minimum of 1 year of experience in collections and/or billing areas within customs agencies. * Knowledge of the SINTAD system (not essential). * Intermediate-level Excel proficiency. * Strong oral and written communication skills. * Organized, responsible, and results-oriented. **Functions:** * Perform daily follow-up on client accounts with outstanding balances. * Contact clients via phone, email, or other means to manage collection of overdue invoices. * Record and update payment information and payment commitments in the system. * Prepare collection reports and alert about potential risks of non-payment. * Coordinate with accounting and commercial departments to resolve specific cases or claims. * Assist in drafting collection letters and other related documents. * Issue invoices, credit notes, and other payment receipts according to internal procedures and tax regulations. * Verify that invoicing is carried out and sent in accordance with each client's instructions. **Competencies:** * Teamwork * Negotiation skills, customer service orientation. * Ability to handle difficult situations with a customer-focused approach. Work schedule: Monday to Friday from 8:00 am to 6:00 pm, Saturdays from 9:00 am to 12:00 pm. General employment regime, formal payroll from the first day. Position type: Full-time, Permanent Work location: On-site