AADE / myDATA: practical checklist for service businesses going digital.

The transition to structured digital record-keeping and live invoice reporting is no longer optional for small enterprises in Greece. Under the strict regulatory updates enforced by the Independent Authority for Public Revenue (AADE), every domestic service business and freelancer must fully transition to the myDATA platform. While large corporations adapted earlier in the year, the final, mandatory deadline for all remaining small businesses and sole proprietors to enforce full B2B electronic invoicing is October 1, 2026.

Managing this transition smoothly without breaking your daily workflow requires an organized, compliant digital setup. Use this practical checklist to ensure your business backend meets the law before the deadline:

• Select your official transmission model: Evaluate whether your monthly invoice volume requires a certified business management software (ERP) connection via an API, or if you qualify to use AADE's free manual web portal, timologio, for your submissions.
• Automate real-time validation: Ensure your billing infrastructure is correctly integrated to transmit transaction data to AADE at the exact millisecond an invoice is issued, instantly pulling back the mandatory unique registration number (MARK) to display on the client invoice.
• Integrate customer tax ID lookups: Implement instant Greek tax ID (AFM) validation fields inside your booking forms or e-commerce checkout systems to cross-reference data with the state registry before submission, entirely preventing data rejection errors.
• Coordinate expense categorization workflows: Set up a clear structure with your accountant to handle how incoming business expenses and outbound invoices are automatically matched and categorized within the myDATA platform to prevent year-end tax discrepancies.

Digital tax compliance does not have to be an operational nightmare. When your booking platform, e-commerce site, or custom web application is engineered to handle these connections quietly in the background, your business stays fully compliant while you focus on serving your clients.