Under certain conditions non-residents can be treated as subject to unlimited income tax in foreign countries.
The advantage of unlimited tax liability on the application is that - unlike limited tax liability - you can take advantage of all personal tax benefits as well as a whole range of family-related benefits. These include the tax deduction of special expenses (like charitable contributions, education expenses, medical and disability expenses, life insurance premiums, mortgage interest expenses).
NOTE: EU citizens are entitled to both federal and regional deductions in Belgium while non-EU citizens are only entitled to federal deductions.
There is a special advantage if you are a citizen of an EU/EEA member state and your spouse or child resides in an EU/EEA member state. In such cases, you can also benefit from family-related tax benefits. All you need is to have an EWR.
The forms, including the one for Non-EU citizens, can be downloaded see the list of different EWR forms we compiled.