Oman Tax Filing Guide 2026

GTA Portal — Electronic Filing

The Secretariat General of Taxation (under the Ministry of Finance) operates a fully electronic tax filing portal. All corporate tax returns and VAT returns must be filed online through this system. Registration on the portal requires a tax ID number (TIN), which is obtained during company registration or VAT registration.

No Individual Filing Requirement

Individuals in Oman do not file personal income tax returns. There is no self-assessment system for individuals. The only tax-related filings required in an individual's capacity are VAT returns (if operating a business exceeding OMR 500,000 turnover) and, in rare cases, filings as a withholding agent for certain cross-border payments. Individual employees have no filing obligations regardless of income level.

Corporate Tax Filing

Corporate tax returns must be filed within 120 days of the end of the company's financial year. The standard tax year is the calendar year (January–December), though companies can apply for an alternate accounting period. Key filing requirements:

• Annual corporate income tax return (Form CIT-1)
• Audited financial statements (mandatory for companies with revenue > OMR 500,000)
• Tax computation showing reconciliation between accounting profit and taxable profit
• Transfer pricing documentation (for related-party transactions exceeding thresholds)
• Tax payment due with the return

VAT Filing

VAT returns are filed quarterly within 28 days of the quarter end. Quarters are calendar quarters (Jan–Mar, Apr–Jun, Jul–Sep, Oct–Dec). The return summarizes output VAT charged, input VAT recoverable, and the net amount payable or refundable. VAT returns also require supporting schedules (purchase ledger, sales ledger).

Penalties

Late filing and payment penalties are strictly enforced:

• Late corporate filing: OMR 200 per month for the first 6 months, then OMR 100 per month thereafter
• Late VAT filing: OMR 500 for the first month, OMR 100 per subsequent month
• Late payment (CIT): 1% interest per month on unpaid tax
• Late payment (VAT): 1% interest per month on unpaid VAT
• Incorrect returns: Penalty of 25% of the additional tax assessed (reducible to 15% if voluntarily disclosed)
• Non-registration: OMR 1,000 for VAT non-registration

Tax Audit and Statute of Limitations

The GTA can audit tax returns within 5 years of filing (10 years in cases of fraud or wilful default). Tax audits are conducted on a risk-based selection. Large taxpayers (revenue > OMR 10 million) are subject to continuous audit programs. Taxpayers have the right to appeal assessments to the Tax Appeals Committee and subsequently to the courts.