Official English to Dutch translation for Belgian Nationality application

I have used http://pauljanssens.be/en/, not cheap, none of the official ones are, but fast, very thorough and accurate.
My Dutch is poor but it is the native language of the wife.

Shop around, I got a 6 page list of people from my commune for document translating services.

Got quotes from €170 to €30 per page, marriage and birth certificates done (to French) including the trip to the palais de justice for €30 each. The original list I got had what languages each offered but I can't find it.

These ones replied with reasonable offers for me, sure at least one of them offered either language. From memory I used the last one, was super easy.

agpha@skynet.be
hedyeh.chinikar@gmail.com
christine_coetsier@hotmail.com
ines@skynet.be

I used Yellow Pages and did everything by phone, snail mail, fax and email.
There is no need for you to actually meet your translator, nor for the translator to be registered at your local court so long as they are registered at a court and get the translations validated at the court where there are registered. You can do the validation yourself - it's free - but it's almost certainly more convenient to pay the translator to get it done for you.
You are looking for a "Beëdigd Vertaler" (Sworn Translator) if you use Yellow Pages.
Sorry I can't remember the details to give you a recommendation as it was several years ago.

To follow up.
I can not disagree with the two previous posts, shop around if you have the time. Janssens were €50 a page.
They also provided a live translator for my marriage in Brussel, not being fluent in any of the three official languages, it was a legal necessity that I understood exactly what was going on.

You need to use an approved person not the cheapest you can find ask the commune for a list.

Please note that not all translators are officially recognised: if you need an official translation it has to be done by a translator listed on internet as Beëdigde Vertaler. I got mine done by Serge Withouck. He is very efficient and reliable, an his charges are good.
http://swts.be/en/
Serge Withouck, Translation Services
Office: +32 (0) 2 513 73 61
Mobile: +32 (0) 475 49 59 30
Fax: +32 (0) 2 626 09 72
Email: info@swts.be /serge.withouck@skynet.be

Dear all, for any sworn translation you can email us at europeannexus@gmail.com for quote, we are situated in Ixelles,
av. Louise, 65 on 4th floor, NEXUS Traduction&Conseil. Sworn at Tribunal de 1re instance.

Beware of North African translator in central Brussels near Midi. He charged less but made my 100 Euro to disappear in addition. He said he is to go to Marocco and needs big Euro notes of money. I counted some hundred notes for him to change with 20's and 50's. He put it on his desk near his laps and the drawer. Before I could turn 100 Euro was missing when he recounted. I couldn't believe that a respectable professional will do that to an unemployed person who is trying to put his papers in order. Some financial terrorism or something? He has been doing it because when i think of the reason for big bank notes, it doesn't make sense! A similar thing happened to my cousin who lost 1800 Euro to a Moroccan in a house rent fraud. He paid the guarantee and collected the key and fake ownership data in contract, but before he could move in, the man asked for the key again to correct a leakage. Then he disappeared. The Police couldn't trace the false name...

I'm an sworn translator English-Dutch and can do this transation for you. My rate is 22 euro/page including the legalisation by court.
contact me: Leen.vansteenkiste@clt.kuleuven.be