E-Invoicing Formats in Oman: UBL, PDF/A-3 & Peppol PINT OM

Oman's Fawtara e-invoicing mandate specified the Universal Business Language (UBL) 2.1 XML, governed by the Peppol PINT-OM specification as their e-invoicing format. If your organisation is in Phase 1 or preparing for subsequent rollouts, understanding which formats are accepted, which are not, and what data your invoices must carry is not optional.

Key Takeaways

• The Oman Tax Authority (OTA) has confirmed that invoices must be issued in XML format as the mandatory structured format under Fawtara. A plain PDF is not an e-invoice.
• The PINT Oman Billing Process defines the data model, business rules, and syntax binding for every Fawtara-compliant invoice.
• The PINT-OM specification uses UBL 2.1 as its XML syntax layer. Hence, your ERP or billing system must generate invoice data in this format.
• A PDF/A-3 is just an addition to the structured XML. It does not carry any legal standing under Fawtara.
• 73 mandatory fields apply under the PINT-OM specification, a significant jump from the 18 to 20 fields required under current Oman VAT legislation.

What is the E-Invoicing Format under Fawtara?

The e-invoicing format under Oman's Fawtara mandate is a structured XML document built on the UBL 2.1 syntax and governed by the Peppol PINT-OM specification. Fawtara is Oman's national electronic invoicing system, introduced by the Oman Tax Authority (OTA) to digitise tax compliance. 

Phase 1 of the Oman e-invoicing went live in August 2026, covering 150 large enterprises. Every invoice exchanged through the Fawtara network must conform to the PINT-OM data model, pass schematron validation at the Accredited Service Provider (ASP) level, and be transmitted via the Peppol five-corner model.

"E-invoicing is the issuance, storage, submission and exchange of invoices electronically through an approved mechanism using a prescribed format/standard, instead of traditional (non-standardized) paper or PDF invoices. A PDF invoice is not an e-invoice." 

What are the Officially Accepted E-Invoicing Formats under Fawtara in Oman?

The OTA has confirmed one mandatory structured format and one permitted human-readable companion format. The table below summarises both.

1. UBL 2.1 XML: The Primary Structured Format

UBL 2.1 XML is the mandatory e invoicing format for all invoices exchanged through the Fawtara network. Here is what this means in practice for your finance and IT teams:

• Every invoice, credit note, debit note, and self-billing document must be generated as a UBL 2.1 XML file.
• The XML must conform to the PINT-OM schematron rules, validated by your Accredited Service Provider (ASP) before the invoice reaches the buyer or the OTA.
• Your ERP system needs to be mapped to produce a PINT-OM-compliant invoice. 

Supported document types under UBL 2.1/PINT-OM: 

2. PDF/A-3: The Human-Readable Companion

PDF/A-3 is an archival PDF format that can embed a structured XML file within it. But, it is not considered an e-invoice. The structured XML is the only legally binding document in Oman. A PDF/A-3 may be used as a human-readable version of the invoice, shared with buyers or retained for internal records, but it carries no legal standing within the Fawtara network.

When is a human-readable version relevant?

• For B2C transactions, the seller must share a human-readable invoice with the consumer, alongside the structured XML submitted to the ASP.
• For export transactions (where the buyer is outside the Peppol network), the supplier submits tax data through the ASPs path and can exchange the human-readable version with the overseas buyer using existing methods.
• The human-readable version must carry a QR code for all B2C transactions, allowing buyers to verify the invoice's authenticity via the OTA's portal/ mobile app. 

Key note: Do not allow your team to treat a PDF export from your ERP as a Fawtara-compliant invoice. The compliance obligation sits with the structured XML, not the PDF.

How Peppol PINT Fits In

Peppol International model for billing (PINT) is the global framework that Oman has adopted and customised as its national e-invoicing specification. It is called PINT-OM, published at docs.peppol.eu/poac/om/

The relationship between these standards is:

• Peppol is the delivery network and governance framework.
• PINT is the global semantic data model for billing documents on that network.
• PINT-OM is Oman's national customisation of PINT, adding Oman-specific business terms (prefixed BTOM), validation rules, and transaction type codes.
• UBL 2.1 is the XML syntax that PINT-OM binds to.

The PINT-OM specification covers three process types: 

1. PINT OM Billing Process: Standard B2B and B2G tax invoices and credit notes.
2. PINT OM Self-Billing Process: Buyer-issued invoices, including import of goods and import of services under the reverse charge mechanism.
3. Oman Tax Data Document (TDD) Process: The regulatory report submitted directly to the OTA (Corner 5) for tax reporting purposes.

Why does this matter for your IT Team? 

Your ASP is required to pass both the Peppol eDelivery Test Suite and the PINT-OM Test Suite for Corners 2 and 3 before receiving OTA accreditation. This means the validation engine your ASP runs is built directly on the PINT-OM schematron rules. If your ERP output does not conform to those rules, invoices will fail at the ASP level, not at the OTA level, and your supply chain will stall.

Which E-Invoicing Format Should You Choose?

There is no choice to make on the structured format: UBL 2.1 XML under PINT-OM is the only accepted e invoicing format for Fawtara. The decision your team actually needs to make is about how you generate and deliver that XML.

For a deeper look at how ERP integration works with Fawtara, reach out to ClearTax e-invoicing specialist here.

Mandatory Data Fields of a Fawtara E-Invoice

The PINT-OM specification sets 73 mandatory fields for a standard tax e-invoice. This compares to just 18 to 20 fields required under current Oman VAT legislation, a near fourfold increase in data requirements.

The mandatory fields fall into six categories:

1. Invoice Header

• Invoice number: Unique identifier assigned by the seller
• Invoice issue date: Date of supply as per VAT legislation
• Invoice type code: 380 for tax invoice, 381 for credit note, etc.
• Invoice currency code: OMR for domestic transactions
• Document-level UUID (BTOM-001): Oman-specific binary transaction type bitmap
• Invoice UUID (BTOM-002): UUID version 5 (name-based, SHA-1)

2. Seller Information

• Seller's legal name
• Seller's VAT registration number (Tax Identification Number/VATIN)
• Seller's Peppol ID (electronic address for network routing)
• Seller's postal address, including country code

3. Buyer Information

• Buyer's legal name
• Buyer's VAT registration number (mandatory for B2B invoices)
• Buyer's Peppol ID or electronic address
• Buyer's postal address and country code

4. Tax Breakdown

• VAT category code per line and at document level
• Taxable amount per VAT category
• VAT amount per VAT category
• Total VAT amount

5. Invoice Totals

• Net amount (excluding VAT)
• Total amount including VAT
• Amount due for payment

6. Line Item Data

• Item description
• Quantity and unit of measure
• Net unit price
• Line net amount
• Oman-specific line-level fields (BTOM-prefixed)

Note: The QR code is mandatory on all B2C human-readable invoices and is generated by the taxpayer (Corner 1). It appears on the human-readable version, not inside the XML. 

For the complete field-by-field breakdown, refer to the Oman e-invoicing data dictionary guide.

The Oman e invoicing format under Fawtara is not a matter of preference; it is a technical mandate. UBL 2.1 XML, governed by the PINT-OM specification, is the only legally valid format for invoices exchanged through the Fawtara network. PDF/A-3 serves a supporting role for human readability, particularly in B2C scenarios, but it does not substitute for the structured XML. 

For finance and IT teams that are preparing for Fawtara compliance, the immediate priorities are:

• Confirming your ERP can produce PINT-OM-compliant UBL 2.1 XML
• Selecting an OTA-accredited service provider
• Mapping your existing invoice data to the mandatory fields 

ClearTax is an accredited e-invoicing solution provider for Oman, with deep integration experience across SAP, Oracle, and other ERP platforms. If your organisation is preparing for Fawtara compliance, speak to our Oman e-invoicing team to assess your readiness and get started.