Tamil Nadu is the eleventh largest state in India and it covers an area of 130058 square Kilometers. Out of the total area a large number is under human habitation. Now to reach every corner of these areas, a geographical demarcation is necessary. In this aspect, the system of Pin Code comes into use. To understand the location of an area or to facilitate the delivery of written correspondences, the use of pin codes are extremely important. A list of the districts of Tamil Nadu, there headquarters and pin codes are given below:
| Districts | Headquarters | Pin Code range startingfrom |
| Coimbatore | Coimbatore | 641001 |
| Cuddalore | Cuddalore | 607001 |
| Dharmapuri | Dharmapuri | 636701 |
| Dindigul | Dindigul | 624001 |
| Erode | Erode | 638001 |
| Kancheepuram | Kancheepuram | 631501 |
| Kanniyakumari | Nagercoil | 629702 |
| Karur | Karur | 639001 |
| Krishnagiri | Krishnagiri | 635001 |
| Madurai | Madurai | 625001 |
| Nagappattinam | Nagappattinam | 611001 |
| Namakkal | Namakkal | 631001 |
| Nilagiri | Udhagamandalam | not available |
| Perambalur | Perambalur | 621212 |
| Pudukkottai | Pudukkottai | not available |
| Ramanathapuram | Ramanathapuram | 623501 |
| Salem | Salem | 636001 |
| Sivagangai | Sivagangai | 630561 |
| Thanjavur | Thanjavur | 613001 |
| Theni | Theni | 625531 |
| Thiruvallur | Thiruvallur | 602001 |
| Thoothukudi | Thoothukudi | not available |
| Tiruchirapalli | Tiruchirapalli | 620001 |
| Tirunelveli | Tirunelveli | 627001 |
| Tiruvannamalai | Tiruvannamalai | 606601 |
| Vellore | Vellore | 632001 |
| Villupuram | Villupuram | 605602 |
| Virudhunagar | Virudhunagar | 626001 |
Apart from these pin codes, other important pin codes of Tamil Nadu are- the capital Chennai with pin codes from 600001, Tirupur with pin codes starting from 641601, Cunoor having pin codes from 643101 and Sivakasi with 626123.
