English use in Brussels

I am considering a job offer in Brussels and I have a dumb/blonde questions on how well can I survive with English alone in Brussels. My potential employer has guaranteed me that from a work standpoint, there are no issues with using English alone. But, I am more concerned with everyday life.

So far, every website that I have visited are in French/Dutch. Therefore, can I get everyday services to be catered to me in English. For example, Online banking, mobile services. Are my bills sent to me in French/Dutch? Just wondering.