The expat community of Hanoi, Vietnam is a transient place. People from all over the world are always coming and going. But while they are here they will usually find an empty room in an apartment or house full of other westerners. They will stay for 6 months or how ever long they see fit and then move on. The Vietnamese government mandates that all residents be officially 'registered' as living at their address with the Police Department. Like most things in this country, there is an extensive swamp of paperwork, 'official' stamps and general bureaucracy to wade through before one can accomplish this. (The Vietnamese really love stamps - big grocery stores even stamp your receipt when you exit.)
To enforce this, the Vietnamese police will do random door-to-door checks of who is living where from time to time. I am not clear on the consequences of being discovered living in your room ‘unofficially’ but from what I gather it will take a substantial bite out of your wallet.
I had been living in Vietnam for 2 months and had yet to register with the police department. Our landlord had been traveling in Thailand for most of the first month and when she returned, the issue remained that she did not speak a word of English. We were all busy so we couldn’t be bothered to hurdle the language barrier. During this time, as far as the Vietnamese government knew, the previous tenant was still living in the room that now belonged to me, which means that he was likely unknowingly registered as living in 2 different houses at the same time. (sorry, man)
Eventually however it came time for me to begin the process of renewing my visa so I needed to get my affairs in order. After a few failed attempts to arrange a meeting with the landlord we were finally able to establish contact. We gave her my registration form and my passport, which had 200,000 VND folded neatly between its pages.
This apparently is the standard price for the bribe to fast-track your registration and avoid having to wade through the aforementioned swamp of paperwork, 'official' stamps and bureaucracy. 200,000 VND is slightly less than 10 USD, not a hefty price by western standards but in local terms a decent chunk of money. We gave her the money and she returned 2 days later with everything taken care of.
So I guess that's that. Now I need to actually start the process of renewing my visa.