A plumber is a person who installs, repairs, maintains and fixes piping that is used in the distribution of water. He also looks for any leakages present in the water distribution system and fixes them. As an expert in his field, he also charges a fee for his services. These are mentioned in detail in the plumber service invoice. In the invoice, it is written that whether something was repaired or whether a totally new thing was kept intact in the place, according to which charges are calculated. They may take nominal charges if something of a lesser degree is done.