Especially in the later game it is difficult and time-consuming to increase your reputation in a town to the required figure for a building license. Of course, steady trade with this town will increase your reputation but it will take some time.
The following hint shows you how to increase your reputation fast – but it is very expensive.

A convoy with a hold of ~2.000 is required, buy 200 units of every item – you can very this number from good to good, e.g. you will rarely sell 200 units meet, but often 200 units of bricks.

Travel to the town where you need to increase your town reputation and reduce the game speed to the lowest available setting. In the ideal case the town lacks most of the goods. As you have all requires goods on board of your convoy, you can sell them up to one green light and your reputation will increase.

As soon as the required figure for the building license is reached, you can stop selling you goods. Go to the master builder und purchase a building license and go back to the harbor dock immediately and buy back your recently sold goods. This way the convoy can be used in another town instantly.