How long is the Belgian Highly Skilled single permit valid, and how do I renew it?

The permit's validity follows your employment contract, capped at three years for each issuance. In your first five years you receive limited-duration permits (an A-card).

To renew, you must apply at the latest two months before the current permit expires, so build in time to gather documents and have your employer act. Applying late risks a gap in your right to stay and work.