Oman clarifies which businesses enter e-invoicing in April 2027

The FAQ clarifies the OMR 5 million test

The update is guidance under Tax Authority Decision 189/2026, not a new legislative amendment. That decision amended the VAT Executive Regulations issued by Decision 53/2021 and set two implementation dates: 1 April 2027 for taxable persons whose annual supplies exceed OMR 5 million and 1 October 2027 for those at or below the threshold. The new FAQ explains how the Authority expects taxpayers to select between those dates.^[1][2]

A taxpayer enters the 1 April phase if either its supplies from 1 April 2026 to 31 March 2027 exceed OMR 5 million or its expected supplies from 1 April 2027 to 31 March 2028 exceed that amount. If neither test is met, the stated implementation date is 1 October 2027. The threshold applies to residents and non-residents; a non-resident counts supplies made in Oman only. A VAT group tests the threshold at group level rather than member by member.^[1]

What counts as annual supplies

The calculation includes taxable supplies other than capital-asset supplies, goods and services subject to the reverse-charge mechanism, and intra-GCC supplies of goods and services. This scope means an ERP revenue figure or one entity's VAT turnover may not be the correct compliance measure. Groups should preserve the actual-period calculation and a supportable forecast, especially where they have several Omani VAT-group members or non-resident registrations.^[1]

The underlying invoice rules still govern

Decision 189/2026 replaces Article 143 of the VAT Executive Regulations. It requires an approved and secure electronic tax invoice with a unique number for supplies, deemed supplies and advance consideration, generally within 15 days of the triggering event. New Articles 143 bis and 143 bis 1 address approved service providers and secure, resilient electronic systems. Article 143 bis 2 permits a taxpayer to request an exception supported by documents and reasons accepted by the Authority, while continuing to file returns and pay tax on time.^[2]

Practical action for multinational groups

MNE tax teams should determine the relevant Oman VAT population, calculate the threshold on the Authority's specified basis and align service-provider, invoice-data and system work to the resulting date. The FAQ describes a five-corner model linking supplier, supplier service provider, buyer service provider, buyer and the Tax Authority, and says voluntary early adoption is available. Detailed technical specifications, provider onboarding and any case-specific exception should be checked separately; the FAQ does not itself grant an exception or change VAT return and payment deadlines.^[1][2]