The IIN is a 6-digit number issued by NPCI that identifies the bank to which the customer's Aadhaar is linked, enabling Aadhaar-based routing.

The standard UPI limit is ?1 Lakh per day. (Note: For specific categories like IPOs, Retail Direct Scheme, and Medical/Education, the limit has been enhanced to ?5 Lakh, but the general limit remains ?1 Lakh).

The National Payments Corporation of India (NPCI) functions as the Bharat Bill Payment Central Unit (BBPCU) responsible for setting standards and operating the BBPS.

The Reserve Bank of India regulates PPIs under the Payment and Settlement Systems Act, 2007. Issuers must obtain authorization from RBI.

The limit for IMPS transactions was enhanced from ?2 Lakh to ?5 Lakh to facilitate larger instant transfers.

e-NACH reduces the turnaround time for mandate registration by using electronic authentication via Netbanking or Debit Card, replacing physical paper mandates.

UPI LITE allows users to make small value transactions (up to ?500) without entering a UPI PIN, improving success rates and reducing load on the core banking system.

Initially set at ?5,000, the RBI enhanced the limit for e-mandates on cards and UPI for recurring payments (like subscriptions, insurance premiums) to ?15,000 without the need for Additional Factor of Authentication (AFA/PIN) during the transaction execution, improving convenience for users.

BBPS has a tiered structure. The Biller Operating Unit (BOU) is the entity responsible for onboarding billers (like electricity boards, telecom companies) into the BBPS ecosystem. The Customer Operating Unit (COU) interacts with the customer (payer).

To enhance security, RBI mandated that merchants and payment aggregators cannot save actual card details (Card-on-File). They must use "Tokens" generated by the Card Network/Issuer. Only the Issuer and Network can store the real data.

NACH Credit is a "Push" system used to distribute funds to many beneficiaries (One-to-Many) like subsidies or salaries. NACH Debit is a "Pull" system used to collect funds from many payers (Many-to-One) like utility bills or loan repayments.

This feature allows Full-KYC Wallet users to scan any standard UPI QR code of a merchant and pay using their wallet balance, breaking the closed-loop restriction of wallets.

FASTag is a reloadable tag employing RFID technology. It is affixed on the vehicle's windscreen and enables automatic deduction of toll charges when the vehicle passes through the toll plaza.

Bharat QR is an interoperable QR code solution that enables customers to pay using their debit/credit cards (by scanning via banking app) without needing a physical POS terminal.

The RBI-DPI comprises 5 broad parameters: Payment Enablers, Payment Infrastructure (Demand-side factors), Payment Infrastructure (Supply-side factors), Payment Performance, and Consumer Centricity. The Base Period for the index has been set as March 2018 (Score = 100). It helps in mapping the deepening of digital payments in India accurately.

A Payment Gateway acts as a technological pipe to transmit data. A Payment Aggregator (PA) facilitates merchants to accept various payment instruments without the need for the merchant to create a separate payment integration system of their own. PAs handle the actual funds, settling them to merchants, and are thus regulated by RBI (Guidelines on PA/PG).

RBI permits FLDG arrangements between Regulated Entities (Banks/NBFCs) and their partner LSPs (Fintechs), subject to a strict cap of 5% of the amount of the loan portfolio. This ensures the lender still holds the primary credit risk while allowing fintech innovation.

While the general UPI transaction limit is ?1 Lakh, NPCI has enhanced the limit to ?5 Lakh for specific use cases like IPO applications, RBI Retail Direct Scheme, and payment for educational/medical institutions to encourage digital adoption for high-value payments.

MMID is a 7-digit random number issued by the bank to the customer upon registration for mobile banking. The first 4 digits represent the unique bank code, and the last 3 digits identify the user account. It enables fund transfers using just Mobile No + MMID, preserving privacy of account details.

NETC (National Electronic Toll Collection) is the flagship program of NPCI developed to meet the electronic tolling requirements of the Indian market using RFID technology (FASTag).

To protect merchant funds, RBI mandates strict settlement timelines. For PAs, the final settlement to the merchant must happen typically by T+1 (where T is the date of transaction capture) to ensure liquidity for the merchant.

IMPS offers two main modes: P2P (Person-to-Person) using Mobile Number + MMID, and P2A (Person-to-Account) using Account Number + IFSC. P2A is useful when the beneficiary is not registered for mobile banking but has a bank account.

NIPL was incorporated in 2020 as a wholly-owned subsidiary of NPCI to internationalize India’s indigenous payment offerings like UPI and RuPay cards, partnering with countries like Singapore, UAE, and Nepal.

The Issuer Bank issues the tag to the customer (vehicle owner). The **Acquirer Bank** onboards the Toll Plaza operator and acquires the transaction when a vehicle passes through, routing it to the Issuer for debit.

"On-us" means the card/account and the terminal belong to the same bank. "Off-us" means they are different (e.g., SBI customer using an HDFC Bank BC point), requiring routing through the NPCI switch.

Agent Institutions recruit and manage physical agents (human touchpoints) to allow cash-based bill payments for customers who are not digitally savvy.

RBI mandates that the core funds of customers in a PPI must not be co-mingled with the company's own funds. An Escrow Account ensures these funds are ring-fenced and used only for settled payments.

RBI mandated authorized Payment System Operators (PSOs) to implement an ODR system for resolving disputes and grievances related to failed transactions in a transparent, rule-based, and automated manner.