In Thiruvallur district, Tamil Nadu, PIN code 600056 is anchored by Poonamallee SO, a Sub Post Office. Mail addressed to this code is sorted through the Southern Postal Region, across 4 listed offices.
| Post office | Type | Full name |
|---|---|---|
| Poonamallee SO | SO | Sub Post Office |
| Kattupakkam BO | BO | Branch Post Office |
| Iyyappanthangal S.O | SO | Sub Post Office |
| Senneerkuppam BO | BO | Branch Post Office |
