Every mobile connection in India is one of two types. With prepaid, you buy a plan or add money first and use the service until it runs out. With postpaid, you use the service through the month and pay a bill afterwards. Both get you the same network, the same calls and the same data.
The difference that matters is control: who decides how much you spend, and when. This guide compares the two on the points that actually affect you, using the rules set by India's telecom regulator, TRAI, and ends with a simple way to choose and a guide to switching.
Prepaid and postpaid in one line each
The basic idea:
- Prepaid: pay first by recharging, then use. When the plan's validity ends or the balance runs out, service stops until you recharge again.
- Postpaid: use first, then pay. You're on a monthly plan, and at the end of each billing cycle you get a bill for the plan and any extra usage.
Side by side
The differences, point by point:
| Compared on | Prepaid | Postpaid |
|---|---|---|
| When you pay | Before using, by recharging | After using, by paying a monthly bill |
| How plans are sold | As vouchers: plan, top-up, special tariff and combo vouchers, under TRAI's rules | As monthly plans billed each cycle |
| Spending control | You can't spend more than you've loaded | Extra usage is added to your bill |
| What you're told | An SMS on every recharge with amount, validity and benefits | A bill for each cycle |
| If you stop using the number | Can't be deactivated for non-usage for at least 90 days; not at all while more than ₹20 is in the account | Can be kept through a safe custody scheme on request |
| International roaming | Off by default; on only at your request | Off by default; on only at your request |
| Moving to another operator | Allowed after 90 days on the network | Allowed after 90 days, once billed dues are cleared |
| Typical fit | Tight budgets, second numbers, variable use | Steady heavy use, families, businesses |
Prepaid: how plans work
TRAI's consumer protection regulations allow prepaid services to be sold only as a few types of voucher. Knowing them makes any plan list easier to read:
- Plan voucher: moves you onto a tariff plan, with no money value of its own.
- Top-up voucher: adds talk-time money to your account, with no restriction on its validity or use. Operators must offer at least one ₹10 top-up.
- Special tariff voucher (STV): a bundle of benefits, such as data, calls and SMS, for a set validity of up to 365 days. Operators must offer at least one STV for voice and SMS only.
- Combo voucher: benefits plus some money value.
Most plans advertised as "recharges" are STVs or combo vouchers. TRAI's September 2026 amendment goes further for people who don't need data: once it takes effect, operators must offer voice-and-SMS-only vouchers at each validity of 30 days or less that they offer for data plans, and one that renews on the same date every month. Our guide to mobile recharge online explains how to choose and check a plan.
Postpaid: how billing works
On postpaid, you choose a monthly plan with a set allowance of calls, data and SMS. Usage within the plan is covered by the monthly charge; usage beyond it, such as extra data or international calls, is charged at the plan's rates and added to the bill. You pay the bill each cycle through the operator's app, your bank, a UPI app or a bill payment platform such as Bharat Connect, which lists mobile postpaid as a category.
Because you're billed after using the service, operators assess postpaid customers before connecting them, and their terms may include a deposit or credit limit. Those conditions are set by each operator, so read them before you sign up.
If you stop using your number
This is one of the least-known differences, and it matters for a second number you rarely use:
- Prepaid: TRAI's rules say an operator can't deactivate a prepaid number for non-usage for at least 90 days, or a longer period the operator sets. While more than ₹20 sits in your account, the number can't be deactivated for non-usage; instead the operator may deduct up to ₹20 to extend the non-usage period by 30 days at a time. Any activity gives you a fresh 90 days.
- Postpaid: operators must run a safe custody scheme. If you ask, they can't deactivate your postpaid number for non-usage, in return for a fee of up to ₹150 for every three months, and they can't charge monthly rental during safe custody. When you want it back, they must restore it within 24 hours of your request.
Your mobile number is the key to your UPI apps and bank alerts, so losing it to inactivity can lock you out of more than calls; our guide to what UPI is explains why UPI is tied to your number. If you keep a rarely used prepaid number for banking, keep a small balance or a long-validity plan on it.
Which should you choose?
A quick way to decide:
| If you... | Usually better | Why |
|---|---|---|
| Want to cap what you spend each month | Prepaid | You can't spend more than you've loaded |
| Use a lot of data every month, and the amount is predictable | Postpaid or a long-validity prepaid plan | Compare the monthly cost of each for your usage |
| Want several family members on one bill | Postpaid, where your operator offers family plans | One bill and shared allowances for several numbers |
| Need a second number for banking or OTPs only | Prepaid | Low cost; keep it active with a small balance or long plan |
| Travel abroad often | Either, with roaming turned on when needed | Roaming is off by default on both |
| Run a business with many staff phones | Postpaid corporate connections | One bill and central control |
Switching between prepaid and postpaid
There are two ways to change, depending on whether you also want a new operator:
- Staying with the same operator: ask your operator to convert the connection. You keep your number, and the operator's own process and conditions apply.
- Moving to another operator: use mobile number portability (MNP). You keep your number, and you can choose prepaid or postpaid with the new operator.
How number portability works
TRAI's mobile number portability FAQs set out the process:
- Send an SMS from the number you want to move: the word PORT, a space, and your ten-digit number, to 1900. You'll receive an 8-digit unique porting code (UPC) from 1901.
- Take the UPC to your new operator's shop or point of sale, fill in its forms and complete KYC, and collect the new SIM.
- You'll get an SMS confirming your request, with 24 hours to withdraw it if you change your mind (by sending CANCEL, a space and your number, to 1900).
- The new operator activates your number, usually overnight with up to four hours without service. Porting within the same service area takes 3 working days, and between service areas 5 working days.
The UPC is valid for 4 days (30 days in Jammu & Kashmir, Assam and the North East). Your request is refused if you've been on your current network for less than 90 days, if you're postpaid with billed dues outstanding, or if fewer than seven days have passed since a SIM swap or replacement. The new operator may charge a porting fee of up to ₹6.46.
Paying for each
Prepaid recharges and postpaid bills can both be paid online, through your operator's app, your bank, UPI apps and bill payment platforms. If a payment goes wrong (money deducted but no recharge, or a bill not marked paid), keep the transaction references: our guide to mobile recharge failed but money deducted explains how to check and get the money back, and our explainer on BBPS and Bharat Connect covers complaints for bills paid through Bharat Connect.
Frequently asked questions
Which is cheaper, prepaid or postpaid?
It depends on your usage. Prepaid usually suits people who want to control spending or use little; postpaid can suit heavy or family use. Compare the monthly cost of comparable plans, including any charges for usage beyond the plan.
Can I keep my number if I switch from prepaid to postpaid?
Yes. With the same operator, ask it to convert your connection. With a different operator, use mobile number portability: send PORT followed by your number to 1900 to get a porting code.
What happens to my prepaid number if I don't recharge?
Under TRAI's rules it can't be deactivated for non-usage for at least 90 days, and not while more than ₹20 sits in your account, though the operator may deduct up to ₹20 to extend the period by 30 days at a time.
Can a postpaid number be kept without paying rental while I'm away?
Yes. Operators must offer a safe custody scheme for postpaid numbers, for a fee of up to ₹150 per three months with no monthly rental during that time.
Why was my porting request rejected?
The usual reasons are being on your current network for under 90 days, unpaid postpaid bills, a SIM swap in the last seven days, or a pending change of ownership. The rejection SMS states the reason.
Official sources
- TRAI — Telecom Consumers Protection Regulations, 2012 (consolidated, 28 Mar 2025)Voucher types (reg. 4); SMS on voucher activation (reg. 6); prepaid non-usage and ₹20 retention (regs. 11–12); postpaid safe custody up to ₹150 per three months, no rental, restoration within 24 hours (reg. 13); international roaming inactive by default (reg. 17).
- TRAI — Telecom Consumers Protection (Thirteenth Amendment) Regulations, 2026 (21 Sep 2026)Voice-and-SMS-only STVs at matching validities of 30 days or less, same-date monthly renewal; in force 30 days after publication.
- TRAI — Mobile Number Portability FAQs (30 Sep 2024)UPC via SMS PORT to 1900; eligibility (dues cleared, 90 days, seven days after SIM swap); UPC validity; 24-hour withdrawal; 3 or 5 working days; up to ₹6.46 per port.
- NBBL — Bharat ConnectBill categories include mobile prepaid and postpaid.
Last reviewed . Examples, amounts and screens marked illustrative are not LILPE figures.
