Hi all!
Reading wikitravel about Benapole (a Bangladesh border town), I've found the following information:
Note: if you arrived by air to Bangladesh, make sure that you have a "change of port" certificate which allows you to leave by land, otherwise you will find yourself being turned back at the border. Change of port certificates are available from the visa office in Dhaka and take about 4 hours to produce. Sometimes you might need to insist here that the office really does provide these certificates and demand that you need one.
I do plan to come Dhaka by plane, get VOA and leave Bangladesh through Benapole.
Do anybody know if I can get the certificate already with VOA or need to find the visa office in Dhaka?
Best Regards
Maciek

