Originally Posted by
bnurkhai
Officially, I see no reason why you should have to have one (regardless of what the website says, kaz and rus don't have open border policies). However, I've heard from a few americans that they were forced to pay for a visa at the airport. I think it depends on what terminal the flight leaves from, but that's just a theory. Side note, you will have to clear immigration in Kazakhstan coming from Russia, however you won't be subject to customs checks.
I think the transit visa requirement has to do with the fact that Russia and Kazakhstan are a customs union. Kazakhstan does not perform customs checks on flights from Russia, but citizens of other countries would still have to be subjected to customs checks somewhere. My assumption is that the customs checks would be performed in the first country of the customs union, which in case would be Russia. Hence, the requirement to have a transit visa in order to clear Russian immigration and more importantly customs inspection.