Electronic invoicing in Oman

Mandatory Use

The implementation of e-invoicing will be mandatory in phases for different taxpayer groups, according to an official timeline that spans from 2026 to 2028:

• Q3 2026 (3rd Quarter 2026): Mandatory e-invoicing begins for the 100 largest taxpayers in the country (large enterprises identified by the OTA). For all other taxpayers, e-invoicing will remain voluntary during this initial phase.
• Q1 2027 (First Quarter 2027): The mandate extends to all large taxpayers. From this point on, all companies classified as large will be required to issue electronic invoices.
• Q3 2027 (3rd Quarter 2027): The requirement expands to cover all businesses for their B2B (business-to-business), B2G (business-to-government), and B2C (business-to-consumer) transactions. 
• Q1 2028 (1st Quarter 2028): Final phase, making e-invoicing mandatory for all G2B (government-to-business) transactions as well.

Invoice Format

So far, the tax authority has not defined official technical requirements for taxpayers and providers. However, it is likely that international standards such as UBL (Universal Business Language) and Peppol interoperability profiles will be used.

Electronic Signature

Currently, no official details have been released regarding the requirement for digital signatures on e-invoices in Oman. The proposed e-invoicing framework may not mandate that each invoice be digitally signed by the issuer. Instead, the system is expected to include built-in authentication and tax validation mechanisms within the platform itself and through service providers to ensure invoice authenticity and integrity.

Invoice Archiving

Regarding the preservation and archiving of electronic invoices, no new specific requirements have been detailed beyond those already established in Oman’s existing tax regulations.

Fiscal Control

The OTA will supervise the system and receive invoice data in real time. Invoices will be validated before being delivered to the recipient, ensuring regulatory compliance and full traceability.

Invoice Workflow

Oman’s e-invoicing system follows the Peppol “five-corner” model. The issuing company generates the electronic invoice from its internal system in a structured format and sends it to its authorized service provider. This provider validates that the invoice complies with the technical and fiscal requirements set by the Oman Tax Authority (OTA), including proper UBL formatting and mandatory fields.

Once validated, the invoice is transmitted simultaneously to the recipient (customer or buyer), typically via their own service provider, and to the OTA through a secure channel. This real-time transmission allows the OTA to register the invoice immediately and, if necessary, carry out automated controls or audits. In certain cases, prior authorization from the OTA may be required before the invoice is considered valid.

Finally, the validated electronic invoice is delivered to the customer in a readable and processable format, allowing for direct integration into accounting systems. The entire process is electronic and automated, ensuring traceability, data integrity, and regulatory compliance in every transaction.