Every filing season the same working paper lands on my desk: foreign salary, RSU sales, a few dividends, all converted at whatever rate Google showed on the transaction date. The math is neat. The rate is wrong. Rule 115 of the Income Tax Rules 1962 prescribes exactly which rate converts foreign currency income into rupees — and, more importantly, exactly which date's rate.
1. TT Buy, not TT Sell. SBI's daily forex card lists several rates per currency — TT Buy, TT Sell, Bill rates, card rates. The rule uses the telegraphic transfer buying rate: what SBI pays to buy your currency. It usually sits below the Google mid-market number, and on a ₹40 lakh RSU sale a rupee of difference moves the gain by tens of thousands.
2. The date is fixed by law, not by your bank credit. For most income the specified date is the last day of the month before the month the income arose. Not the day the money landed. Not an average. When that last day has no published SBI card, practice is to step back to the last published one and note it in the file.
3. It covers accrued income, not just received income. RSU vesting is a salary perquisite under Section 17(2) the moment it vests, whether or not you sold a share. The vest-month conversion sets your cost of acquisition for every future capital gain on those shares.
From 1 April 2026 the Income-tax Act, 2025 replaces the 1961 Act, and the Income-tax Rules, 2026 replace the 1962 Rules. The conversion rule is renumbered: Rule 115 becomes Rule 206, and the TT buying rate definition moves from Rule 26 to Rule 207. The mechanism is identical — same SBI rate, same specified dates. Income of FY 2025-26 and earlier cites Rule 115; FY 2026-27 onward cites Rule 206. The side-by-side mapping is on our SBI TT rates page.
"Specified date" is the whole game. Here is the mapping for the income that shows up in foreign-equity filings, each with a worked example using the month-end rates published on our free rates page:
| Income | Specified date (rate to use) | Example |
|---|---|---|
| Salary, incl. RSU / ESOP perquisite at vesting | Last day of the month immediately preceding the month the salary fell due (or was paid in advance or arrears) | RSUs vest 15 Feb 2026 → 31 Jan 2026 USD TT buy, ₹91.35 |
| Dividend from a foreign company | Last day of the month immediately preceding the month the dividend was declared, distributed or paid | Dividend paid 18 Nov 2025 → 31 Oct 2025 rate, ₹88.20 |
| Capital gains — sale consideration | Last day of the month immediately preceding the month of transfer | Shares sold 15 Apr 2026 → 31 Mar 2026 rate, ₹93.15 |
| Capital gains — cost of acquisition (bought / vested in foreign currency) | Same logic, applied at the month of purchase or vesting | Shares vested 10 Sep 2025 → last published Aug 2025 card (30 Aug), ₹87.70 |
| Foreign bank interest (other sources) | 31 March — the last day of the previous year, one rate for the whole year | Interest credited through FY 2025-26 → 31 Mar 2026 rate, ₹93.15 |
| Any of the above where TDS applied | Proviso overrides: rate on the date tax was required to be deducted | US broker withheld tax on a 10 Nov 2025 dividend → TT buy of 10 Nov 2025 itself, not month-end |
| Foreign tax credit (Rule 128, Form 67) | TT buying rate on the date the foreign tax was actually paid | Foreign tax paid 10 Nov 2025 → TT buy of 10 Nov 2025 for the Form 67 credit |
Two rows trip people up constantly. Foreign bank interest is not "interest on securities" — it falls under other sources and takes one 31 March rate for the whole year, not twelve month-end rates. And the cost side of a capital gain has its own date, at the month of purchase, not the month of sale: a share vested in September 2025 and sold in February 2026 uses two different SBI rates in the same computation.
| Transaction | Rule 115 rate date | Used for |
|---|---|---|
| RSU vesting (perquisite income) | Last day of month preceding the vest month | Salary perquisite; sets cost of acquisition for future capital gains |
| RSU sale (capital gains) | Last day of month preceding the sale month | Sale consideration in INR for Schedule CG |
| Dividend received | Last day of month preceding the payment month | Dividend income in INR; Form 67 computation |
| Schedule FA A3 — initial value | Rate on the day of investment | Initial investment value in Schedule FA |
Schedule FA reports foreign assets held during the calendar year ending 31 December, not the financial year. Its conversion dates are its own: initial investment at the investment-date rate, peak balance at the rate on the date the peak occurred, closing balance and income at the 31 December rate. For calendar year 2025 that closing rate is the 31 Dec 2025 USD TT buy of ₹89.47, straight off our rates page.
TT Sell is not TT Buy. I have seen working sheets built on the Sell column that overstated income on every line.
Yen is quoted per 100 units. An SBI card showing 55.00 against JPY means ₹55 per 100 yen. Skip the division and your income is a hundred times too large. Thai Baht follows the same convention.
Month-ends fall on Sundays. No CBDT circular prescribes a fallback. The defensible practice is the last preceding published card, applied consistently and noted in the working papers.
Averages are not a thing. The rule names one date per income item. An annual average has no basis in Rule 115 or Rule 206, however tidy the spreadsheet looks.
The RBI reference rate is not this rate. The RBI stopped publishing it in 2018; FBIL computes a benchmark now. Neither is what the rule asks for. In scrutiny, "SBI TT buy, 31 January 2026, per Rule 115" is an answer. "Google" is not.
Under Section 270A of the Income Tax Act, under-reporting of income attracts a penalty of 50% of the tax on the under-reported amount — 200% where it amounts to misreporting. A wrong conversion rate on a large RSU sale is exactly the kind of gap that surfaces in scrutiny, because the AO can recompute it from public data in minutes. And skipping Schedule FA is costlier still: Section 43 of the Black Money (Undisclosed Foreign Income and Assets) and Imposition of Tax Act, 2015 carries a ₹10 lakh penalty for failing to disclose a foreign asset in the return, even where the income itself was fully taxed.
GainSutra maintains the month-end SBI TT Buy series and applies the correct Rule 115 rate to every vest, sale and dividend in your broker statement — Fidelity, Schwab, Morgan Stanley, EquatePlus, Computershare, Merrill, UBS — without manual lookup.
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