Bearings: the financial year, the players, the portals
Almost every deadline a company faces is calculated from a single anchor point: the closing date of the financial year. The financial year is set by the articles of association and, for the vast majority of Luxembourg companies, coincides with the calendar year. Closing on another date is possible but remains the exception; it follows exactly the same rules, only the concrete dates shift. This guide therefore expresses deadlines as “year end + X months” where the law does, which holds for everyone, and only mentions fixed dates where they really are fixed (tax advance payments, VAT).
A second bearing serves for direct taxes: the tax year, i.e. the calendar year in which the financial year closes. For a company with a calendar financial year, it is simply the year of that financial year; the notion only matters for the rare companies with a non-calendar year end, dealt with further on.
The players, finally: the management body (manager or board of directors) draws up the accounts; the general meeting approves them; the supervisory auditor (commissaire aux comptes) or the approved statutory auditor reviews them where the law or the articles require it; filing with the Trade and Companies Register (RCS) goes through the eCDF portal and then the Luxembourg Business Registers desk; tax returns pass through MyGuichet.lu (direct taxes) and eCDF (VAT); social security filings through the channels of the Joint Social Security Centre (CCSS).
Accounting obligations: keep, draw up, approve, file
| Obligation | Deadline | Basis |
|---|---|---|
| Preparation of the annual accounts by the management body | Before the approval meeting (in practice: year end + 4 to 5 months) | Law of 10 August 1915 (LSC) |
| Report of the supervisory auditor or the approved statutory auditor | Before the meeting, on the basis of the accounts drawn up | LSC; law of 19 December 2002 (LRCS) |
| General meeting approving the accounts | Year end + 6 months at the latest | LSC |
| Filing of the annual accounts with the RCS (via eCDF) | Within one month of approval and no later than year end + 7 months | LRCS, art. 75 |
| Retention of books and records | 10 years | Commercial Code |
Bookkeeping. Every commercial company keeps accounts in line with the standard chart of accounts (PCN, plan comptable normalisé) and retains its books and supporting documents for ten years. It is the raw material for everything that follows: books kept up to date as you go make every deadline in this calendar easy; books reconstructed at year end make them all difficult.
Drawing up and review. The management body draws up the annual accounts (balance sheet, profit and loss account, notes and, where applicable, management report) early enough for the statutory reviewer to prepare its report before the meeting. Two review regimes coexist. The société anonyme is always subject to review: by a supervisory auditor (commissaire aux comptes), or by an approved statutory auditor where its size so requires. The approved statutory auditor (réviseur d'entreprises agréé) becomes compulsory, whatever the legal form, as soon as the company exceeds, at the close of two consecutive financial years, two of the three thresholds defining a small company: €7.5 million balance sheet total, €15 million net turnover, 50 employees on average. Below that, a SARL is subject to no statutory review, unless the articles or the shareholders decide otherwise.
Approval. The annual general meeting is held no later than six months after year end, on the date set by the articles. For a SARL, the decision may be taken in writing if the articles allow it and if the number of shareholders does not exceed sixty; above that threshold, the SARL must hold a meeting and appoint a supervisory auditor.
Filing. The approved accounts are filed with the RCS within the month following approval and, in any event, no later than seven months after year end. Filing takes place in two steps: entry and validation of the accounts on the eCDF platform (balance sheet and profit and loss account in the standard format), then filing of the complete package (accounts, notes, reports, resolution on the allocation of the result) on the Luxembourg Business Registers portal. Small companies may file an abridged balance sheet and notes and are exempt from the management report; medium-sized companies (up to €25 million balance sheet total, €50 million turnover, 250 employees) benefit from more limited relief; above that, everything is complete and published.
Direct taxes: file, pay in advance, withhold
| Obligation | Deadline | Detail |
|---|---|---|
| Corporate income tax / municipal business tax return (CIT / MBT, form 500) | 31 December of the year following the tax year | Tax year = calendar year of the year end |
| Net wealth tax return (NWT) | Same deadline, attached to the CIT/MBT return | Wealth assessed at 1 January |
| CIT advance payments | 10 March, 10 June, 10 September, 10 December | Fixed dates, whatever the year end |
| MBT and NWT advance payments | 10 February, 10 May, 10 August, 10 November | One month offset from CIT |
| Tax balance after assessment | Within one month of notification of the assessment | Appeal possible within 3 months |
| Withholding tax on dividends | Return and payment within 8 days of the dividend being made available | Form 900; exemptions depending on the recipient |
| Wage tax withholding (RTS, retenue d'impôt sur traitements et salaires) | No later than the 10th of the month following the period | Monthly, quarterly or annual frequency depending on amounts |
| Salary account statements / annual certificates | Early the following year | Electronic transmission to the ACD and delivery to employees |
The annual return. The company files, on a single form, corporate income tax (CIT), municipal business tax (MBT) and net wealth tax (NWT). Since the 2022 tax year, the deadline is 31 December of the year following the tax year; filing is electronic, via MyGuichet.lu. The return relies on the approved annual accounts, which are attached if they have not yet been filed with the RCS. Hence the value of sequencing things: accounts, meeting, filing, return.
Advance payments. The tax office sets quarterly advance payments based on the last tax assessed (or an estimate for a new company). They follow fixed calendar dates: 10 March, June, September and December for CIT; 10 February, May, August and November for MBT and NWT, a one-month offset that many finance teams discover too late. Late payment carries interest of 0.6% per month. When the result of the current year looks very different from the previous one, a reasoned request to reduce the advance payments may be filed at any time; it is an often-neglected cash-flow lever.
The assessment and the appeal. After examining the return, the administration issues a tax assessment; the balance is payable within one month of notification. The taxpayer has three months from notification to lodge an appeal with the director of the Luxembourg Inland Revenue (ACD).
Withholding taxes. Two flows have their own calendar. Withholding tax on dividends (15%, unless exempt or a treaty rate applies) is declared and paid within eight days of the dividends being made available, on form 900; the deadline therefore depends on the resolution allocating the result, i.e. on the general meeting. Withholding tax on wages and salaries is paid no later than the 10th of the month following the withholding period, on a monthly, quarterly or annual basis set by the administration according to the amounts withheld. Early in the year, the employer also transmits the salary account statements for the past year.
Special cases. Family wealth management companies (SPF) are not subject to CIT, MBT or NWT, but pay a quarterly subscription tax. SOPARFIs, for their part, fall under the ordinary regime described above, with the exemptions specific to income from participations.
VAT: a frequency set by turnover
| Annual turnover excl. VAT | Regime | Periodic returns | Annual return |
|---|---|---|---|
| Up to €112,000 | Annual | None | Before 1 March of the following year |
| €112,000 to €620,000 | Quarterly | Before the 15th of the month following the quarter | Recapitulative, before 1 May |
| Over €620,000 | Monthly | Before the 15th of the following month | Recapitulative, before 1 May |
Registration. Everything starts with the initial declaration to the Registration Duties, Estates and VAT Authority (AED), to be filed within fifteen days of the start of activity. It is on the basis of estimated turnover that the administration assigns the filing regime; it then revises it at year end if the activity has changed scale. The regime is not a choice of the taxable person.
Small business exemption. Below €50,000 of annual turnover (with a tolerance for exceeding up to €55,000), the business may fall under the exemption scheme: no VAT charged, no deduction, lighter filing obligations. Opting for the normal regime remains possible and is often worthwhile as soon as there is investment.
Periodic returns. The return and the payment are due before the 15th of the month following the period, month or quarter. The administration grants a filing tolerance (two months for periodic returns, longer for the annual return), but it only concerns filing: payment remains due on the legal date, and interest runs. All returns go through eCDF, online form or XML file.
Annual return. It is the only return under the annual regime (before 1 March) and a recapitulative return under the quarterly and monthly regimes (before 1 May): it consolidates the year, corrects discrepancies and lets the administration reconcile the periodic returns with actual turnover. It follows the calendar year, which coincides with the annual accounts of most companies.
Intra-EU transactions. Supplies of goods and services to taxable persons in other Member States give rise to a recapitulative statement, filed at the same frequency as the VAT return; above €50,000 of intra-EU supplies of goods in a quarter, it becomes monthly. Distance sales and certain services fall under the OSS and IOSS schemes, with their own quarterly or monthly returns.
Social security: the monthly rhythm of the CCSS
A “complete” calendar cannot ignore social security obligations, even if they are not the main subject of this guide. From the first employee, the employer registers with the CCSS and declares every hiring and every departure within eight days. Each month, it transmits the salary declaration for the past month, no later than the 10th of the following month, then pays the contributions on the basis of the account statement the CCSS sends it, within the period it states. The self-employed come under the same body, with contributions calculated on declared income and adjusted after tax assessment. These deadlines follow the calendar month.
A company's typical year, and the case of a non-calendar year end
Here, for a small SARL under the quarterly VAT regime, with one employee and a dividend decided at the general meeting, is what the rules above mean in practice over a year. The first column describes the general case, a 31 December year end. The second illustrates the exception, a 30 June year end: the fixed dates (advance payments, VAT, social security) are identical, only the deadlines linked to year end shift, and the tax return follows the tax year, i.e. the calendar year of the year end.
| Deadline | Year ending 31 December N | Year ending 30 June N |
|---|---|---|
| Approval meeting (year end + 6 months) | 30 June N+1 | 31 December N |
| RCS filing (year end + 7 months, within a month of the AGM) | 31 July N+1 | 31 January N+1 |
| Dividend withholding tax (AGM + 8 days) | 8 July N+1 if AGM on 30 June | 8 January N+1 if AGM on 31 December |
| CIT / MBT / NWT return | 31 December N+1 | 31 December N+1 (tax year N) |
| CIT advance payments | 10 March · 10 June · 10 September · 10 December, every year | |
| MBT and NWT advance payments | 10 February · 10 May · 10 August · 10 November, every year | |
| Quarterly VAT | 15 April · 15 July · 15 October · 15 January | |
| Annual recapitulative VAT return | 1 May, for the past calendar year | |
| CCSS salary declaration and wage tax withholding | The 10th of each month, for the previous month | |
Reading the two columns side by side shows the essential point: a non-calendar year end lightens nothing, it moves the peaks of workload. It is one of the reasons why the calendar financial year remains the norm in Luxembourg, and our default recommendation at incorporation.
Summary: your calendar, month by month
Choose your financial year end and your VAT regime: the timeline recalculates. By default, it describes the general case, a 31 December year end under the quarterly regime.
How to read it: the general meeting is held no later than six months after year end, the RCS filing seven months after, the dividend withholding tax follows the meeting by eight days, and the tax return is due on 31 December of the year following the year end. The timeline illustrates the rules at month level, ignoring weekend and public holiday postponements, and without the administrative VAT filing tolerance (about two months for periodic returns, more for the annual return), which applies only to filing and never to payment. It does not replace the schedule drawn up for a given company.
This calendar describes the rules applicable at the date of publication; thresholds and deadlines change regularly and we update this page when they do. For a given company, good practice is to draw up, from incorporation, a schedule specific to its VAT regime and its social security situation, then to keep to it. That is precisely what we do for our clients: every deadline is anticipated, prepared and filed on time, and you are warned before it arrives, never after.