This document outlines key accounting, tax compliance and reporting deadlines in Luxembourg. It provides the statutory filing deadline of 31 December 2018 for 2017 financial statements and tax returns. It also lists the deadlines for FATCA, CRS and country-by-country reporting requirements for financial institutions and multinational enterprise groups. Missing certain deadlines, such as one set by a filing injunction issued by the tax authorities, may result in fines being imposed.

1. Loyens & Loeff Luxembourg
2017 Financial
Statements
(book year = calendar year)
2017 Tax Returns
(book year = calendar year)
Reporting
FATCA/CRS/CbC
(book year = calendar year)
Cheat Sheet – Luxembourg’s key accounting, tax compliance and reporting deadlines
Q1
2019
Statutory Filing
Deadline
Missing the deadline
leads to an increased
filing fee.
Statutory Filing
Deadline
This deadline is generally
not enforced as it predates
the statutory filing date for
financial statements; missing
it should not lead to fines.
Filing Reminder
Issued*
This reminder typically
imposes a deadline of 31
December 2018, missing it
should not lead to the fine
mentioned in the reminder.
Filing Injunction
Issued*
This Filing Injunction typically
sets a deadline in May 2019,
missing it results in the fine
mentioned in the Filing
Injunction.
Actual Filing
Deadline*
Pursuant to the Filing
Injunction, a fine is imposed
if this deadline is not
respected.
FATCA & CRS
Filing Deadline
For FATCA & CRS 2018
Reporting for Financial
Institutions.
31 December
2018
31 July
2018
Q4
2018
30 June
2018
May
2019
31 March
2018
1 January
2018
CbC
Reporting Deadline
For filing CbC Reporting
2017 for CbC Reporting Entity.
+
Notification
by Constituent Entities of a CbC
Group for 2018 CbC Reporting.
*Based on prior years’ practice.
**Deadline based on info from informal discussion with Luxembourg tax authorities.
Surcharge**
A surcharge of maximum
10% on tax due can be
imposed in case of late filing,
filings made later than 12
months after closing of the
book year are likely to be
considered late.