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28.4 Tax Filing Requirements and Deadlines

Understanding Tax Filing Obligations​

All companies in Luxembourg must file corporate tax returns and pay taxes on time. Understanding filing requirements and deadlines is essential for compliance and avoiding penalties.

Filing Requirements​

Who Must File​

All Companies Must File:

  • All registered companies (SA, SARL, SCS, SNC, etc.)
  • Regardless of profit or loss
  • Even if no tax is due
  • Must file annual tax return

What Must Be Filed​

Required Documents:

  1. Corporate Tax Return: Complete tax return form
  2. Financial Statements: Annual accounts (balance sheet, income statement)
  3. Supporting Schedules: Detailed schedules and calculations
  4. Supporting Documentation: Invoices, contracts, etc. (if requested)

Filing Deadlines​

Standard Deadline​

Filing Deadline: 7 months after fiscal year-end

Example:

  • Fiscal year-end: December 31, 2024
  • Filing deadline: July 31, 2025

Payment Deadline​

Payment Deadline: Same as filing deadline (7 months after year-end)

Important: Tax must be paid by filing deadline, even if return is filed earlier

Extension Requests​

Requesting Extensions​

Extension Available:

  • Can request extension of up to 3 months
  • Must request before original deadline
  • Extension applies to both filing and payment

Extension Process:

  • Submit extension request to tax authorities
  • Provide justification for extension
  • Receive approval (usually granted if reasonable)

Extended Deadline:

  • Original: 7 months
  • Extended: Up to 10 months after year-end

Tax Return Contents​

Required Information​

Tax Return Must Include:

  1. Company Information: Name, address, RCS number, tax ID
  2. Fiscal Period: Start and end dates
  3. Revenue: Total revenue and breakdown
  4. Expenses: Total expenses and major categories
  5. Tax Adjustments: All adjustments to accounting profit
  6. Taxable Profit: Calculated taxable profit
  7. Tax Calculation: Corporate income tax, municipal tax, employment fund
  8. Tax Credits: Any applicable tax credits
  9. Tax Due: Final tax liability

Supporting Schedules​

Common Schedules:

  • Depreciation schedule
  • Interest expense schedule
  • Related-party transactions
  • Tax loss carry-forwards
  • Investment allowances

Electronic Filing​

eCDF Platform​

Electronic Filing:

  • Tax returns filed through eCDF platform
  • Same platform as VAT returns
  • Electronic submission required
  • Paper returns generally not accepted

eCDF Process​

Steps:

  1. Log in to eCDF
  2. Select corporate tax return
  3. Enter all required information
  4. Upload supporting documents
  5. Review and validate
  6. Submit electronically
  7. Pay tax through eCDF

Payment Methods​

Payment Options​

Available Methods:

  1. Bank Transfer: Direct transfer from eCDF
  2. Online Banking: Link to online banking
  3. SEPA Direct Debit: Automatic debit authorization
  4. Credit Card: Credit card payment (fees may apply)

Payment Confirmation​

After Payment:

  • Receive payment confirmation
  • Keep confirmation for records
  • Payment appears in eCDF system

Late Filing and Payment Penalties​

Late Filing Penalties​

Penalties:

  • €250 - €2,500: Fixed penalty for late filing
  • Additional penalties: For very late filing
  • Interest: On unpaid tax from due date

Late Payment Penalties​

Penalties:

  • Interest: Charged on overdue amounts
  • Additional penalty: For persistent non-payment
  • Collection action: For serious non-payment

Luxembourg Compliance Note​

Critical Requirements:

  • File on time: Late filing results in penalties
  • Pay on time: Late payment results in interest and penalties
  • Accurate returns: Errors can trigger audits
  • Keep records: Maintain all supporting documentation
  • eCDF filing: Must file electronically through eCDF

Best Practices:

  • Start early: Begin preparation well before deadline
  • Organize documents: Keep all tax documents organized
  • Review carefully: Review return before submission
  • Professional help: Use tax advisor for complex situations
  • Calendar reminders: Set reminders for deadlines

Think It Through​

TechLux Solutions has a fiscal year ending December 31. Their tax return preparation is delayed, and they won't be ready by July 31. What should they do? What are their options?

Concepts in Practice​

Tax Filing Process

TechLux Solutions tax filing:

Fiscal Year: January 1 - December 31, 2024 Filing Deadline: July 31, 2025

Preparation Timeline:

  • January-February: Gather documents
  • March-April: Prepare financial statements
  • May: Calculate tax adjustments
  • June: Complete tax return
  • July: Review and file

Filing Process:

  1. Complete tax return form
  2. Prepare supporting schedules
  3. Review all calculations
  4. Log in to eCDF
  5. Enter return information
  6. Upload supporting documents
  7. Review and validate
  8. Submit electronically
  9. Pay tax through eCDF
  10. Receive confirmation

Result: Return filed on time, tax paid, no penalties.