Masons belonged to a guild but this was not part of only one town - members of the mason were required to move to wherever building was needed. The Mason’s Guild was international and it was sometimes known as the Freemasons since ‘free’ stone was stone which was used often by masons due to its softness and ability to complete detailed carvings.
Masons went to wherever there was employment and other tradesmen could remain in one place as there was enough trade for their skill to enable them to settle in the same location. Masons on the other hand had to travel to their next employment source after a building was finished, and this could be considerably far away.
A mason at the top of his trade was called a master mason and he had total charge over a building site - all masons would work below him. The master mason also took charge over carpenters and glaziers and generally anyone who worked on a building site. Master masons would work separately in the mason’s lodge. Important building sites would all have had a workshop building and drawing office where all the building site work was organised. Anyone arriving at the site and claiming to be a master mason would first be tested by the master mason and other master masons already on the building site. This was so they could make sure a good level of quality was kept and so there would be a good chance of building work in the future.
Masons would have an apprentice to assist them, and whenever the mason moved on to a new role his apprentice would travel there too. Once a mason felt his apprentice had enough skills and knowledge about the trade, he would have an exam at a mason’s lodge. If the apprentice passed this exam he would be appointed to that lodge as a new master mason and awarded a unique mason’s mark. After he received this, the young master mason would include it on any work done by him so it could be seen as his work.
See also: Medieval Guilds
"Medieval Masons". HistoryLearning.com. 2015. Web.