Expatriates who have been living in Belgium for ten years or more are to be investigated by the taxman in relation to a special expat tax status.
This requires them to have their private and economic interests outside the country and the argument is that for many of those who have stayed for a decade this is no longer the case.
Some 3,000 expats are thought to be affected by the move, which will see Belgian authorities carrying out a full audit on employees going back to their first day of work in the nation, reports Expatforum.com.
Companies where there are more than ten members of staff claiming the special tax status will be the first to be scrutinised, but all expats who have worked there for more than ten years will be investigated, whether they have been in one job or more.
A letter has already been sent to the firms that will be audited, asking them to create a list of all their expat employees that have the special status.
The benefit of being categorised as an expat in this manner is to gain tax concessions due to the temporary nature of their time in Belgium.
This means they are treated as non-residents and only their Belgian income is taxed, as opposed to any other assets as well.
Initial applications for the status require evidence of continued ties with the expat's home country, such as household bills or insurance.
The problem is that there has been no ongoing system to check the temporary nature of a person's stay in Belgium after the initial stages, which is why this auditing is now due to take place.
Once the list of expats receiving the status has been sent from a company, the authorities will look at various factors to decide where their private and economic interests lie.
These will include the location of any property owned; where the children go to school; and the working life of any spouses or partners.