Is there any time limit on when a work permit must be renewed after extension of stay has been granted? Can I wait until say the day before the work permit expires to renew it, or do I have to renew it immediately after receiving an extension stamp?

As long as you renew your work permit before it expires whether this is done 1 week or 1 day before it doesnt matter .. just don't let your work permit expire.

Is there any time limit on when a work permit must be renewed after extension of stay has been granted? Can I wait until say the day before the work permit expires to renew it, or do I have to renew it immediately after receiving an extension stamp?

Not sure neither what you're say nor what your asking. Your workpermit is never valid longer than to the expiry date of the latest extension stamp in your passport ... (at the time you last got a stamp in your workpermit - that is).

Have a look in your work permit - it will tell you that your workpermit is valid until some date (that'll correspond to some expiry date of some (outdated) stamp in passport ... If you didn't renew your workpermit on (or before) its valid-until-date, it's invalid (actually).

Edited October 24, 200619 yr by Cyberstar

Ok, maybe I wasn't clear enough. My previous extension stamp (and my work permit) expires in the middle of next month. I recently got a new extension-of-stay stamp that expires a week later. So, is it necessary for me to renew my work permit immediately now that I got the stamp, or can I wait until the day before the work permit expires?