PIN codes are made up of 6 digits. The first two digits denote the state and the next 4 digits the district, sub-area and the sorting area. The PIN codes that start from 20 to 28 belong to Uttar Pradesh. There are 71 districts in the state that have been allotted PIN codes by the Indian Postal Department. Some of the most famous districts that have been allotted PIN codes are Agra, Mathura, Aligarh, Lucknow, Meerut, Mirzapur, Ghaziabad, Varanasi, Sultanpur and many more. With the introduction of these Pin codes, the efficiency of the Indian Postal Department has gone several notches higher that what it was earlier.