Cheapest way to keep a second SIM active
A second SIM — a backup number, a work line, a data-only device — usually only needs to stay alive. So the right recharge is the one with the lowest cost per day, not the one with the most data. Here is the cheapest keep-alive plan on each operator:
| Operator | Cheapest keep-alive plan | Validity | Cost / day |
|---|---|---|---|
| BSNL | ₹397 | 150 days | ₹2.6/day |
| Jio | ₹91 | 23 days | ₹4.0/day |
| Vi | ₹1,699 | 365 days | ₹4.7/day |
| Airtel | ₹1,799 | 365 days | ₹4.9/day |
Not sure which plan fits you?
See minimum recharge options →Yearly beats monthly for a spare number
Paying once a year almost always costs less per day than topping up every month, and it removes the risk of the number lapsing because you forgot a monthly recharge. If your second SIM does nothing but receive OTPs and the occasional call, a long-validity or annual pack is the cheapest and safest choice.
Which operator for a second SIM
BSNL is usually the value winner — its annual and long-validity plans have the lowest cost per day, so a backup number on BSNL can cost just a few rupees a day. If you want your spare on the same network as your primary for coverage reasons, check that operator's annual pack in the table above; the per-day difference is often small.
See the full BSNL recharge plans for the cheapest long-validity options, or the minimum recharge hub to compare across all four operators.
If the second SIM also needs a little data
If your spare occasionally needs data — for a hotspot or a dual-SIM phone — pick a long-validity plan that bundles some data rather than a data voucher, so validity and data expire together. Answer a few taps in the finder and it will pick the cheapest option for exactly that pattern.