guest/subtenant issue

My landlord has had previous problems with subletters and is now very up tight about people having guests in the building. Do I have to notify him if I have friends staying for a few days if I lend them my keys whether I am here myself or not? And is it illegal to let a friend stay in my apartment for a week or so when I am away on a business trip? If the landlord believes guests are paying subtenants and not guests, can he terminate my lease/bring to court?

Thanks

Subtenants are probably not allowed, but I'd have to read the lease and know the local ordinances to give you a real binding answer. Generally you can have a guest over -- unless the lease says otherwise. Getting paid by the guests is a always a no no. I don't thnk you want to have to get the landlord's permission otherwise.