Swap residency

i have a question can swap my eu permanent resident card here in beglium can anybody tell me what is the possiblity to swap and requirement to swap

A bit more details will help our members to suggest.

Which country's residence permit do you currently have ? When you move to Belgium, will you have a job in hand ?

i have eu resident permanent ec card from spain and i have a job offer also but the case is......is not a highly qualified job .....so is there any chances to swap my long term ec card.