Search Year Permit

If your friend gets a Annex 33, that means he is a 'border student’.

His commune may think since he has a valid residence permit of The Netherlands, France, Germany or Luxemburg, it is not needed to issue any paper to come/stay/work here. In my experience, they don't issue anything before your RP expires

He should better inform his commune about his residence permit is about to expire and will need annex 15 to stay before his application for search year is completed.

@ashiseverywhere Thank you for your response. He has informed his commune and they told him that they cannot do anything or issue any paper until they get a response from the immigration office.

@tosinosu

i agree with the comment above, that his RP from another country is expiring and that he may need Annex 15 as a valid residence permit pending the result of his search year. not all municipality clerk understood this clearly so your friend has to be precise in explaining the situation, perhaps visiting the municipality if possible.

@tosinosu

The commune can definitely issue annex 15 for your friend if

1. he is already registered in the foreigners' registrations
2. his application for a search year is timely and complete 15 days before his Annex 33 expired.

In result, his stay as a student expires while it is being processed, the municipality will issue an Annex 15.

But I think, in his case, it is when his residence permit of the other EU country expires. But he must get a clear answer from the city hall before it expires. @brla15 is right. Not all clerk know the procedure. Try to talk to another officer. Google translate everything your friend want to explain in advance if your friend doesn't speak Dutch or French. It may also help. 

The worst/faster cause is he need to contact the Belgian Embassy or Consulate of the country of his residence.