What is an SO post office in India?

SO stands for Sub Office. Sub Offices are larger local post offices that report directly to the Head Office of their district. They handle delivery for a specific area or locality, operate full postal services, and receive mail dispatched from the Head Office.

What is a BO post office in India?

BO stands for Branch Office. Branch Offices are the smallest and most numerous type of post office in India, and are especially common in rural areas. They report to a Sub Office (not directly to the Head Office) and typically offer a limited range of postal services. Many Branch Offices operate out of a single room or a counter in a village.

Do HO, SO, and BO all share the same PIN code?

Not necessarily. Each post office has its own PIN code, but post offices that serve the same delivery area may share a PIN code. In many cases, a locality is served by one delivery post office (usually a BO or SO), and all addresses in that locality use that office's PIN code.

How many HO, SO, and BO post offices are there in India?

As of the latest India Post data, there are approximately 919 Head Offices, around 24,000 Sub Offices, and over 130,000 Branch Offices in India — totalling more than 155,000 post offices nationwide.

HO, SO, and BO Post Offices — What's the Difference?

1 May 2026·3 min read

If you've ever looked up a PIN code on indianpincode.com and noticed the "Office Type" column showing HO, SO, or BO — here's what those labels actually mean and how the three tiers of India's postal network fit together.

Head Office

~919 nationwide

•One per postal sorting district
•PIN code ends in 001 for that district
•Runs the central sorting operation for the district
•All Sub Offices and Branch Offices in the district are under its jurisdiction

Reports toDirectly to the Postal Division

ExampleDelhi GPO (110001), Mumbai GPO (400001), Chennai GPO (600001)

Sub Office

~24,000 nationwide

•Serves a specific area or locality
•Receives dispatched mail from the Head Office
•Can have multiple Branch Offices reporting to it
•Usually open full working hours, 6 days a week

Reports toHead Office of their district

ExampleConnaught Place SO (110001), Andheri SO (400053), Anna Nagar SO (600040)

Branch Office

~130,000 nationwide

•Smallest type of post office
•Most are in rural and semi-urban areas
•May operate from a single room or shared space
•Many are managed by a single Gramin Dak Sevak (GDS) employee

Reports toSub Office (not the Head Office)

ExampleMost village and rural post offices are Branch Offices

How They Fit Together

Head Office (HO)

dispatches sorted mail to ↓

Sub Office (SO)

delivers mail to ↓

Each HO serves multiple SOs. Each SO serves multiple BOs. Mail flows down this chain from the sorting centre to your doorstep.

Why Does the Office Type Matter?

The type of post office that serves your address affects delivery speed and service availability. Mail addressed to a Head Office or a large Sub Office in an urban area typically gets delivered faster than mail going to a rural Branch Office.

For e-commerce and logistics, knowing whether a PIN code is served by an HO, SO, or BO is a useful proxy for delivery capability. Urban HOs and SOs typically support same-day or next-day courier services; rural BOs may only see weekly postal rounds.

On indianpincode.com, every post office listing shows its type (HO, SO, or BO) alongside its GPS coordinates, so you can quickly understand the postal infrastructure for any PIN code.

Frequently Asked Questions

HO stands for Head Office. It is the main post office of a postal district, responsible for receiving and dispatching all mail for that district. Every sorting district in India has exactly one Head Office, and its PIN code always ends in 001 (e.g., 110001 for Delhi GPO, 400001 for Mumbai GPO).

Related Guides

What Each Digit in a PIN Code Means

The History of PIN Codes in India

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