The interval is four weeks. That's four weeks after you've taken any action or after their last reply. Take a look at some dates from my timeline: MEDICALS 23/07/2013 & 22/08/2013, VISA GRANT 24/09/2013 . I've had the first round of medical checks on 23/07/2013. Four weeks later, I received the call from IOM telling me they'd made a mistake and that I needed to undergo more tests, which I did the next day - on 22/08/2013. Another four weeks passed, nothing happened, I wrote that e-mail and on 24/09/2013 I received a visa. So, whatever goes wrong prolongs your wait for about a month . It's strange, though, that you've had no feedback since 07/09/2013. I don't know why they're keeping you in the dark.