11 March 2011 Update - The IUC charges have changed again, if you drive a vehicle with high CO2 emmissions then expect a big increasing in your IUC (Road Tax) this year.
If you are considering buying a second hand car in Portugal or importing one it is worth considering how much the annual road tax (IUC) will be. The system of Road Tax on Portuguese registered cars changed in June 2007.
If the car you are buying was registered after 30th June 2007, or was re-registered after this date the new system applies. It is calculated based on the CO2 level and the engine size.
The system changed from Imposto Municipal Sobre Veiculos (IMS) to Unico de Circulção (IUC) and the amount you pay on newer cars increased considerably.
It used to be that the tax was due in a specific month of the year(June/July) but now it is due within the month of original registration, in the case of imported cars this is the month of re-registration (matriculation). This means that even if you have an older car an it was re-registered after June 2007 it will be taxed as a new car and the IUC will be MUCH higher than an older car.
e.g. Ford Mondeo 1.8 1997 first registered in Portugal will cost €33,10 however if it was imported after the change it willl cost €274,54 - over 800% more!!
You no longer have to display the stamp in your car but you are now obliged to carry the receipt as proof of payment.
You will not get any postal reminder of this (like you do for IPO). Yyou have to note it in your diary/calendar and make sure you pay it on time.
NB. If it is even 1 day late you will pay a fine of €15 and if you are stopped by the GNR and found to be driving without Road Tax the fine will be higher.
If you look at the article Importing a Car & Paying Tax! There is a simulation to find out the IUC for your car.