What Invoice Requirements for Estonia Companies?

Short answer: Registration number, VAT number (if applicable), sequential numbering, professional PDF format, VAT breakdown, reverse charge notation.

Mandatory Fields for Estonian OÜ Invoices

Your Company Information (Seller)

• Company Name: Full legal name ending in OÜ (e.g., "YourCompany OÜ")
• Registration Number: 8-digit Estonian registry code from e-Business Register
• Registered Address: Complete Estonian address on file with government
• VAT Number: EE format if VAT-registered (required above €40,000 revenue threshold)
• Contact Information: Email address, phone number, website (optional but recommended)

Customer Information (Buyer)

• Full Name or Company Name: Legal entity name
• Billing Address: Complete address including country
• VAT Number: Required for B2B EU transactions (reverse charge applies)
• Registration Number: Helpful for B2B validation

Invoice Details

• Unique Invoice Number: Sequential with no gaps (INV-001, INV-002, etc.)
• Invoice Date: Date of issue
• Payment Due Date: Terms (e.g., Net 30)
• Order Reference: Transaction ID or order number for tracking

Financial Breakdown

• Product/Service Description: Clear description of what was sold
• Quantity: Number of units or licenses
• Unit Price: Price per item
• Net Amount: Subtotal before VAT
• VAT Rate: 22% (standard Estonia rate), 9% (reduced), or 0% (reverse charge)
• VAT Amount: Tax collected or €0.00 if reverse charge
• Gross Total: Final amount due

VAT-Specific Requirements

If Your OÜ is VAT-Registered

• Display your Estonian VAT number (EE format)
• Show VAT breakdown on all invoices
• Apply reverse charge for B2B EU transactions
• Note "Reverse charge applies" when applicable
• Submit monthly or quarterly VAT returns to Maksu- ja Tolliamet

If Your OÜ is Not VAT-Registered

• No VAT number required (revenue under €40,000 threshold)
• No VAT breakdown on invoices
• Still need all other mandatory fields
• Monitor revenue to register when approaching threshold

Estonian Reverse Charge Rules

When reverse charge applies to your invoice:

• Your OÜ has Estonian VAT number
• Customer has EU VAT number
• Different countries (not both Estonia)
• B2B digital services transaction

Invoice must show:

• Both VAT numbers displayed
• 0% VAT rate applied
• "Reverse charge applies" notation
• Reference to EU Directive 2006/112/EC (optional but professional)

Estonian Accounting Standards

Sequential Numbering

Estonia requires continuous invoice numbering with no gaps:

• ✅ Correct: INV-001, INV-002, INV-003, INV-004
• ❌ Wrong: INV-001, INV-002, INV-004, INV-007 (gaps present)

Professional Format

Estonian accountants and the Tax Authority expect:

• PDF Format: Not Excel, Word, or plain text
• Professional Layout: Clear structure and readable typography
• Complete Information: All required fields populated
• Accurate Calculations: VAT amounts must be mathematically correct
• Proper Currency: EUR symbol for euro transactions

Maksu- ja Tolliamet (Estonian Tax Authority) Compliance

Your invoices must comply with:

• Value Added Tax Act (VATA): VAT regulations for invoicing
• Accounting Act: General accounting standards
• Income Tax Act: Business expense documentation
• EU VAT Directive 2006/112/EC: Cross-border transactions

Common Estonian Accounting Software Compatibility

Our invoices work with:

• Merit Aktiva: Most popular for e-Residents (PDF import and manual entry)
• Directo: Enterprise-level accounting system
• Horizon: Common for OÜ businesses
• Excel-Based Systems: Manual bookkeeping workflows

E-Resident Specific Considerations

Digital Business Infrastructure

• All invoices can be generated remotely from anywhere in the world
• No physical presence in Estonia required
• Digital signatures not required for standard invoices
• Email delivery acceptable for invoice submission

Cross-Border Operations

• Your Estonian OÜ can invoice customers worldwide
• EU reverse charge simplifies B2B VAT compliance
• Non-EU customers typically 0% VAT (export of services)
• Estonian accountant handles VAT returns and compliance

What Happens If Invoices Are Non-Compliant?

Missing required fields can result in:

• Accountant Rejection: Invoices sent back for correction
• VAT Return Issues: Cannot claim VAT deductions or submit accurate returns
• Audit Problems: Tax authority may request corrections during audits
• Customer Payment Delays: B2B customers may refuse payment for non-compliant invoices
• Penalties: Fines for repeated non-compliance with Estonian accounting regulations

Example: Complete Estonian OÜ Invoice

Related Questions

• Is this compliant with Estonia accounting rules?
• How do Estonia e-Residents generate invoices?