I and a friend are planning a cross-Asia journey from Malaysia to India. I've decided to stay around north India and then move overland into Pakistan, then Iran and finally Turkey. With Iran, is it easy to actually get into the country? I'm British if that makes a difference either way! Would I be able to apply for an Iranian Visa in Lahore or Karachi for example? Also how long would it take to receive a visa after applying?
As a British national,you should take part in a tour and be accompanied by a tour guide to travel in Iran and accommodate in the hotels.In the visa application form the MFA should be informed about the hotels and itinerary in Iran. After having the reference number, the visa can be collected in two working days by direct referral or in one working week by posting the docs to the Iran embassy.
You should hire your guide or take the tour from the agency which applies for your visa. Moreover, the same agency should book your hotel as well, so it is better to take your all inclusive tour from that particular tour operator.
For more information about visa check this page: Iran visa.