Worked on enhancing cross-border invoicing reliability in the devcode-it/openstamanager repository by addressing a critical issue affecting electronic invoice generation for foreign clients. Focused on backend development using PHP, the solution enforced country-specific data formatting rules, such as setting the postal code to 00000 and omitting the province field for non-Italian destinations. This approach resolved XML generation errors caused by non-conforming address values, ensuring invoices for foreign customers met external compliance standards. The work improved the system’s resilience to regulatory changes and reduced processing failures, with all changes clearly documented for traceability and future maintenance within the project’s codebase.