# Electronic Commerce Operator (ECO) — Concept & Tax Liability
## Who is an ECO?
Electronic Commerce Operator = Any person who owns, operates or manages an electronic platform for the supply of goods or services.
Examples: Amazon, Flipkart, Uber, Swiggy, Zomato, OYO, Urban Company.
## Why a Special Provision?
Unlike a normal 2-party transaction (Supplier ↔ Recipient), an ECO transaction has three parties — Supplier, Recipient, and the ECO platform itself. GST law therefore creates special rules to fix tax liability.
## Two Categories of ECO Transactions
| Nature of Supply | Who Pays the Tax? | TCS Obligation? |
|---|---|---|
| Notified services u/s 9(5) of CGST / 5(5) of IGST | ECO pays tax (as deemed supplier) | No TCS |
| Any other supply through ECO | Actual supplier pays tax | ECO collects TCS |
## Who is the Person Liable When ECO Lacks Presence?
```
Is ECO in taxable territory?
├── YES → ECO itself pays the tax (for notified services)
├── NO, but has a representative there → Person authorised by ECO pays
└── NO presence and no representative → ECO must appoint a person for paying tax
```
## Other Cross-Cutting Provisions
1. Aggregate Turnover: Supplies made through an ECO count toward the supplier's aggregate turnover, NOT the ECO's.
2. Invoicing under 9(5): Where ECO pays tax (notified services), the invoice is raised by the ECO, not the actual supplier.
3. Two key downstream concepts: Notified Services u/s 9(5) and Tax Collected at Source (TCS) — see separate lessons.