Jean-Paul Olinger, director of the Luxembourg Tax Administration (ACD), spoke with RTL Radio on Wednesday about the ACD's accelerating digital transformation, with 17.7% of declarations now filed online and plans to reach 85% by 2028.
So far, around 26,000 tax declarations have been submitted electronically this year, representing 17.7% of all declarations, up from about 10% the previous year, Olinger said. He added that this was a noticeable increase, but acknowledged that 75% of declarations still need to be filed before the end of the year, as many taxpayers traditionally wait until December to submit their forms.
The ACD expects a late-year surge but is prepared to handle it both digitally and on paper, according to Olinger.
Simplifying tax filing
Earlier this year, the ACD sent invitations to around 20,000 households to take part in the 123EASY programme, a simplified digital filing process where the ACD pre-fills the return and the taxpayer only needs to review and sign it. Olinger said the goal is to reach 100,000 such automatic declarations by 2028, mirroring systems already in use abroad.
Asked whether citizens might distrust a pre-filled declaration prepared by the tax office, Olinger dismissed the concern, stating that their priority is accurate taxation and that they assume taxpayers are honest. He added that the ACD's outreach campaign, ACD on Tour, aims to inform and reassure the public through direct contact and online resources.
Technical issues and digital know-how
Some taxpayers experienced difficulties uploading their declarations at the end of last year, but Olinger said those problems were mostly due to incorrect file handling rather than system errors. Submitting the form incorrectly, for example by opening the PDF in the wrong viewer, can corrupt the file and prevent successful upload, he said.
Despite these hiccups, he said most people are managing well with the technology.
Currently, PDF-based forms are still printed and checked manually at tax offices because the IT system has not yet been fully digitalised. However, Olinger explained that a new backend platform is in development, with a public tender under way and teams being set up to work alongside external IT providers.
Accuracy and audits
A recent parliamentary question revealed that 80% of the 9,500 electronically filed declarations reviewed by the ACD contained corrections, prompting questions about accuracy. Olinger cautioned against misinterpreting the statistic, explaining that many of those adjustments were made at taxpayers' own request, for example to add forgotten expenses or income.
Olinger explained that the figure also includes cases flagged by the system or checked due to alerts from abroad. In 2024, Luxembourg's tax authorities exchanged 3.7 million data records with foreign administrations, which often trigger later adjustments, he said.
He stressed that most electronic filings are processed correctly: around 20% of reviewed files were confirmed accurate without changes, and the majority of the remaining 21,000 declarations were also deemed correct after verification.
The advantage of the electronic route, he noted, is speed. Returns are often processed within two weeks, although files may still be subject to review for up to five years, as permitted by law, Olinger said.
Future improvements and automation
The ACD plans to expand its pre-filled declaration system, giving taxpayers access to data already held by the administration, such as salary, tax withholding, and family status. Olinger explained that by 2027, the system should also integrate information from banks and insurance companies, with the cooperation of the ABBL and ACA.
Olinger emphasised that Luxembourg's system remains declarative: taxpayers are responsible for confirming their own information, and the state respects privacy rules that limit automatic data collection.
Regarding the new online tax assistant, he rejected claims of calculation errors, stating that the system uses the same calculation engine as traditional filings and that they're working to make the interface less technical and more user-friendly.
Finally, Olinger confirmed that the administration receives around 200 complaints per month, and new staff are being hired to handle them. Despite the hurdles, Olinger remains confident that the direction is set and that they'll keep working to make the system better.
