Airtel and BSNL main balance recharge

not really. in so far as I recollect they had the same ✯444✯PlanMRP# method, and it worked.
(it asked for the confirmation via the on-screen popup menu and once request sent by user, the confirmation SMS message came).

however, for reference/ recollection or otherwise, we always preferred the ‘selfcare SMS’ method.
it serves as proof and recall both.

→MTP plan12345← sent to 123
or
→sub vstv12345← or →sub dstv12345←sent to 123
where “12345” needs to be replaced with actual plan MRP.
for pre-paid users this worked well.
VSTV being voice special tariff voucher
DSTV being data special tariff voucher
PV (plan voucher) are meant for extending SIM/ number validity.

depending on circle or circumstances, most combo packs (of Data, Calling, SMS, free name tunes/ caller tune) are referred to and activated as VSTV.

shifting/changing from one PV to another (even changes like shift from per minute to per second pulse) may not be possible from main balance
however if the number/SIM does have existing outgoing validity, then subscribing to renewing the running PV is possible (from USSD or self-care messaging).

BSNL website, when using their ‘quick recharge’ section, mostly provides circle specific information
buyt in the rare scenario, where recent changes/ new launches aren’t updated then it is prudent to cross check with customer care.
Caution: Customer care too isn’t 100% foolproof. sometimes they too are unaware of changes, are new or uninterested joinees and misinformed or don’t research correctly.

though BSNL lets most plans be activated from main balance, many agents (at one time) would simply misinform that plans with free PRBT (caller tunes, name tunes) would not activate from main balance.
(in our experience, they were wrong. the plans got activated)

since most activities except core office work is outsourced and even customer service is handled by private agencies, often times
connecting to support is difficult and even futile.
(many agencies faced political arm twisting to shut down offices in one region and club/expand in area where certain thugs wanted to show growth/vikaas)
in such cases, or when in peak times.. connecting to CS is unfeasible
★one can send any of the following service response messages to: 123 ★ and get details of at-least few of the available packs for the number/ respective circles

★STVHLP DATA★ ↔ 123
★STVHLP VOICE★ ↔ 123
★STVHLP SMS★ ↔ 123

sending ↑such↑ texts to 123, gets one the list of available bundles as a reply message.
but sometimes the message/s get truncated after 320 characters or so (that’s why i mentioned ‘at-least some of the’ bundles.)
the reply messages list them in ascending order of prices.

in so far as i kmow, ALL these bundles CAN be activated by ‘self-care messages’ (sent to 123) or by USSD requests.
★query and request messages sent to 123 are not charged★ (main balance only deducted as per MRP of the PV or STV. for few months, earlier, even taxes were waved off so deduction used to be M.R.P. minus G.S.T.).

if there is no valid PV on a number, then the user cannot renew the PV.
in simple terms: if one wants seamless connectivity (or have panicky senior citizen users) then you got to waste one day validity by activating the plan “before” midnight or plan expiry time.

even in case one doesn’t do so, if sufficient available main balance is there, then (BSNL) system will debit the account within 3 hours of expiry of the way PV, to let the SIM have validity extension.
(i.e., if one forgets to or chooses not to manually renew the validity, the system will do it between midnight and 4a.m. “after” outgoing validity stops).