Residency permit renewal

hi,

I am about to have my residency permit renewed for another 5 year period.(I live in Brussels) The last 2 times I received a paper residency card - in principle I am fine with receiving a paper card, but I am wondering if it will be a problem over the next 5 years if I keep filling in my taxreturn on paper as I have done until now, eg. in the future it will only be electronic. Hence, should I request an electronic card so I can fill in the taxes on the web, but then my next q is, I have never received any instructions on how to do this, eg. I just get the taxform on paper in the post and I fill it in and mail it back, so not sure how to fill in the taxes electronically. I would need an e-card reader right?

Any advice? Many thanks for all responses in advance