ZATCA has implemented e-invoicing in two phases: 

Phase 1: Generation 

• Phase 1 (December 2021) 
• This phase is a ‘generation phrase’ that is focused on generating compliant electronic invoices in the required format (XML or PDF/A3 with embedded XML). Through a complaint e-invoicing solution, taxpayers must develop and maintain tax invoices, simplified tax invoices, and corresponding CDNs. 
• This phase was put into effect by ZATCA on December 4, 2021. All taxpayers (except from non-resident taxpayers) and any other parties submitting tax invoices on behalf of VAT- exempt providers are required to compile it. 

Phase 2: Integration 

• Phase 2 (January 2023): 
• This is an Integration phase, requiring businesses to connect their systems with ZATCA’s platform for direct exchange of invoices and transaction data. In this phase, ZATCA’s systems are integrated and technical and commercial requirements for electronic invoices and electronic solutions are introduced. To exchange data and information, taxpayers must link ZATCA’s systems with their own for the purpose of issuing electronic invoices, debit notes, and credit notes. 
• The Tax Invoice from ZATCA must be “cleared” by the seller in real time before being sent to the purchasers as a legitimate e-invoice. Simplified invoices must be reported to ZATCA by the seller, nevertheless, within 24 hours of the invoices’ creation.