I am visiting Iran in September with a tour company and have recently received my Letter of Invitation, which I'm told is valid for 1 month from the date of issue. As I understand it, getting the visa finalised is pretty much just a formality now and involves a trip to London, a little paperwork and paying some fees.

Unfortunately, it's really unclear from the info I have where in London I need to go to complete the process. There is the Consulate of the Islamic Republic of Iran in Kensington, or the Embassy of the Islamic Republic of Iran in Knightsbridge. Calling either results in spending a couple of hours on hold in a queue and then the place closing with me no closer to an answer.

My timing for getting this sorted is pretty tight because I'm told the LoI is only valid for 1 month from the date of issue, and it arrived a few days ago whilst I was away in Portugal, so the clock is already ticking. I'm committed to a trip to Germany over the August bank holiday weekend and I need to find a slot in the next week where my employer will let me take more time of to get down to London. It's a long way for me, the Embassy/consulate isn't open every day and I can't afford not to get the visa, not have the passport back in time for for Germany or cancel the Germany trip.

Any help on where to go, when and what to expect would be greatly appreciated.