The 0.02% Dilemma: Why Zerodha and INDmoney Are Sounding the Alarm on UPI’s New Capital Market MDR

Beginning October 15, 2026, capital market transactions—including fund top-ups for stockbroking trading accounts, mutual fund purchases, and primary equity applications—will be subject to a Merchant Discount Rate (MDR) of 0.02%, capped at ₹300 per transaction.

While a 2-basis-point charge appears minuscule compared to traditional credit card MDRs (which hover between 1.5% and 2.5%), top industry founders argue that applying ad-valorem payment charges to discount broking models creates an unsustainable structural mismatch.

The Economic Mismatch: Flat Brokerage vs. Ad-Valorem MDR

The tension stems from a fundamental disconnect between how digital brokers make money and how payment processing fees are calculated:

• Fixed Revenue Model: Discount brokers like Zerodha, Groww, and Angel One operate primarily on a flat fee structure—typically charging ₹20 per executed order, irrespective of trade size (or ₹0 on equity delivery).
• Ad-Valorem Cost Model: Under the new 0.02% MDR framework, the payment gateway cost scales directly with the amount transferred into the account.

How the Math Breaks Down for a Discount Broker:

├── Deposit: ₹50,000 ──> MDR Cost: ₹10 (50% of gross brokerage revenue)

├── Deposit: ₹1,00,000 ──> MDR Cost: ₹20 (100% of gross brokerage revenue)

├── Deposit: ₹5,00,000 ──> MDR Cost: ₹100 (5x the maximum brokerage revenue earned)

└── Deposit: ₹15,00,000 ──> MDR Cost: ₹300 (15x the gross brokerage revenue earned)

If an active derivative or equity trader transfers ₹1,00,000 via UPI into their trading terminal and executes a single trade generating ₹20 in brokerage, the entire fee is swallowed by the UPI MDR.

The "Ghost Transfer" Problem

Compounding the problem is an operational reality unique to capital markets: fund additions do not equal trade executions.