Three different structures, not three versions of the same thing
PPF (Public Provident Fund) is built around annual contributions over a mandatory 15-year lock-in (extendable in blocks of 5 years after that), currently paying 7.1% p.a. compounded annually. NSC (National Savings Certificate) is a one-time lump-sum investment with a fixed 5-year tenure, currently paying 7.7% p.a. compounded annually but paid out only at maturity. KVP (Kisan Vikas Patra) is also a one-time lump-sum investment, but instead of a fixed tenure it simply doubles your money over a published "doubling period" — currently 115 months (about 9.6 years) — with no fixed end date tied to a calendar tenure the way NSC has.
Tax treatment is the biggest practical difference
PPF is fully "EEE" (Exempt-Exempt-Exempt): the annual contribution is deductible under Section 80C, the interest earned is entirely tax-free, and the maturity amount is tax-free too. NSC's principal is Section 80C-deductible, but the interest it earns is taxable as income each year (even though it's paid out only at maturity) — a detail many investors miss, since there's no interim payout to remind them. KVP gets no Section 80C deduction at all, and its interest is fully taxable — it's the most tax-inefficient of the three, though it's also the simplest to understand: your money doubles, full stop.
A worked lump-sum comparison — NSC vs KVP
Since NSC and KVP are both lump-sum instruments, they compare directly: ₹1,50,000 invested in NSC grows to about ₹2,17,355 after its fixed 5-year tenure (about ₹67,355 interest). The same ₹1,50,000 in KVP takes longer — about 9.6 years (115 months) — but simply doubles to exactly ₹3,00,000 (₹1,50,000 interest) by definition of how KVP is structured. Per year, NSC's 5-year payout works out to a faster effective annual return, but KVP's doubling guarantee is easier to reason about for a saver who doesn't want to do the compounding math themselves.
Why PPF doesn't fit into that same comparison
PPF can't be compared to NSC or KVP on the same lump-sum basis, because it's structured as an annual contribution over a mandatory 15 years, not a single deposit. Contributing the Section 80C maximum of ₹1,50,000 every year for the full 15-year term grows to about ₹40,68,209, of which about ₹18,18,209 is interest — every rupee of that tax-free, unlike NSC's taxable interest. The right way to think about PPF isn't "does it beat NSC's rate" but "am I able to commit to a 15-year annual savings habit" — if yes, its EEE tax status makes it hard to beat for that specific, long, disciplined horizon.
Choosing between them
Pick NSC when you have a lump sum and a roughly 5-year horizon and still want a Section 80C deduction. Pick KVP when you want the simplest possible "doubles in X years" guarantee and don't need a tax deduction or a fixed calendar-year tenure. Pick PPF when you can commit to annual contributions for the long term (15+ years) and want the strongest tax treatment of the three — many long-term savers use PPF as their core long-horizon holding and NSC or KVP for shorter-term lump sums that don't fit PPF's multi-year commitment.