Apply for a street trading licence
A pedlar or a street trader
A pedlar must keep moving, and can only stop to trade. If you are standing still, waiting for customers, you are street trading and could be prosecuted.
If you are a pedlar, you must either carry the items you are selling or carry them on a trolley.
You need to be on foot, and your trolley needs to be easy to move around. Guildford town centre is on a steep hill and can be very busy. If you cannot easily move your trolley and have to stay in one place because of this, you are street trading and will need the council's permission.