India does not wait until July to collect income tax. It collects as you earn — through TDS if someone else pays you, and through advance tax if the TDS falls short. Salaried people mostly never notice, because payroll does it for them. The moment you add freelance income, large capital gains, rent or interest, the machinery becomes your problem, and it charges interest when ignored.
TDS: collection at the source
Tax Deducted at Source makes the payer the collector: your employer on salary, your bank on FD interest, your client on professional fees, even your tenant on high rents. Each deduction lands against your PAN in Form 26AS/AIS, and at filing it is simply credit already paid. The TDS calculator shows the common sections and rates.
Two habits prevent most TDS grief: reconcile 26AS against your own records before filing, and remember that TDS is not the final tax — a 10% deduction on fees means nothing if your slab rate is 30%; the difference is yours to pay.
Advance tax: the four-date calendar
If your remaining tax for the year — total tax minus TDS and credits — comes to ₹10,000 or more, you owe it in instalments during the year itself:
- 15 June — 15% of the year's tax paid cumulatively
- 15 September — 45%
- 15 December — 75%
- 15 March — 100%
Miss an instalment and interest under s.425 (the old §234C) runs at 1% a month on the shortfall for that quarter. There is a small mercy in the first two dates: paying at least 12% by June (or 36% by September) avoids interest entirely. But the relief is a cliff, not a taper — pay 11% and interest is computed against the full 15%, not against the 12% trigger you just missed.
Fall below 90% of the year's tax by 31 March and a second clock starts: s.424 (the old §234B) charges 1% a month from 1 April until you settle. The advance tax calculator runs the full schedule, including both interest heads and the rounding rules.
The practical difficulty is estimation: June's instalment prices a year you have barely started. The working method is to re-estimate each quarter and true up — the schedule is cumulative, so a strong second half simply raises the December and March payments.
The presumptive shortcut
A freelancer or small business on the presumptive scheme (s.58 of the new Act, the old §44AD/44ADA) pays the entire year in one instalment by 15 March — capping s.425 exposure at one month, and turning four estimation problems into one. It is a genuinely underrated part of the scheme's appeal, covered in freelancing and presumptive tax.
⚠️ The Income-tax Act, 2025 renumbered these sections (234B→424, 234C→425, 44ADA→58); rates, dates and thresholds are statutory values the Budget can revise. Verify current figures before relying on them — this is arithmetic, not tax advice, and WealthTicker is not a SEBI-registered investment adviser.
Key takeaway
TDS is a running prepayment, not the final bill, and advance tax fills whatever gap remains once it crosses ₹10,000 for the year. Know the four dates — 15/45/75/100 by June, September, December and March — respect the cliff in the early triggers, and stay above 90% by year end or a second interest clock starts in April. If you qualify for presumptive taxation, the whole calendar collapses to a single March payment.
More in Module 11 — Money beyond funds: salary, tax, loans and property
Decoding your CTC: why in-hand is so much less
Cost to company is what employing you costs, not what you are paid. The four layers inside a CTC, where EPF and gratuity actually go, and the basic-salary split that silently sets three benefits at once.
Old vs new tax regime: the choice that decides everything else
The new regime is the default and usually the winner — but not always. Where the break-even sits, why the §87A rebate never touches capital gains, and why the regime decides whether ELSS, HRA and 80D planning are worth anything at all.
ESOPs, RSUs and ESPPs: taxed twice, at two different prices
Slab tax on the discount when shares become yours, capital gains from that day's FMV when you sell. Why tax can fall due on paper value, and why the cost-basis error is the most common mistake in self-filed returns with equity comp.
Freelancing full-time: the 50% deal most professionals miss
Presumptive taxation lets a qualifying professional declare half of gross receipts as profit — no books, no audit, one advance-tax instalment. How the scheme works, and how to compare a salary and a freelance offer honestly.
How an EMI actually works (and the flat-rate trick)
Interest on the outstanding balance first, principal with the remainder — so early years barely repay anything. Why tenure sets total interest, why early prepayment punches above its weight, and why a flat rate is roughly double what it claims.
A surplus and a loan: prepay, refinance or invest?
Prepayment is a guaranteed, tax-free return equal to your loan rate — cut the tenure, not the EMI. When a balance transfer clears its fees, and when investing the surplus honestly beats both.
Rent vs buy: the honest math
Terminal net worth on two fully-specified paths, with the renter investing every rupee the buyer sinks. The two assumptions that decide the answer, and the tax change that flipped older calculators' verdicts.
The small savings family: PPF, SSY, NSC, KVP, SCSS and kin
One sovereign family, priced quarterly. Which schemes compound, which pay income, which are tax-exempt — and why the after-tax yield, not the poster rate, is the number to compare.
Insurance is not an investment: term plans and the LIC question
Bundled policies do both jobs badly. Sizing a term cover from needs rather than folklore, and evaluating an endowment you already own on forward numbers alone — surrender, paid-up or continue.
What trading actually costs: beyond zero brokerage
STT, exchange charges, GST, stamp duty and DP fees stack on every trade no broker can waive. The break-even move to know before a trade, the averaging-down trap, and what leverage really multiplies.
Running a small business by the numbers
Break-even and the margin of safety, margin versus markup, the cash conversion cycle, the DSCR a lender will compute anyway, and GST as an input-credit chain — the five checks that catch trouble early.