A resident's fixed deposit interest is only subject to TDS once it crosses a threshold in a financial year, and even then at a modest rate, while resident savings account interest isn't subject to TDS at all. NRO fixed deposits work differently: because Section 194A (the resident TDS-on-interest provision, with its exemption threshold and savings-account carve-out) doesn't apply to non-residents, NRO interest — savings or fixed deposit — falls instead under Section 393(2), which has no equivalent basic exemption. Whatever interest an NRO FD credits, some of it is withheld before it ever reaches the account holder.
The default rate
Bank NRI-desk pages commonly cite a flat 30% TDS rate on NRO FD interest by default, before adding applicable surcharge and a 4% health and education cess. Note that this figure isn't perfectly uniform across sources — at least one tax-reference source describes Section 393(2) interest withholding closer to 20% plus surcharge/cess as a general rate — so treat 30% as the widely-cited figure for NRO FD interest specifically, but confirm the exact current rate (and the surcharge slab, which depends on the account holder's total income and can range considerably) before assuming a single all-in percentage.
Unlocking the treaty rate instead of waiting for a refund
The default domestic rate isn't necessarily the rate the India-US DTAA (or India's treaty with another country of residence) actually allows on interest income. Submitting a Tax Residency Certificate (TRC) from your country of residence, along with Form 10F and your PAN, to the bank before the interest is credited can let the bank apply the lower treaty rate at source instead of the default rate — avoiding the wait for a refund entirely. Submitted after the interest has already been credited, this generally doesn't work retroactively; the overpayment then has to be recovered by filing an Indian income tax return instead.
The TDS-on-NRO-interest calculator on the NRE/NRO & TDS page lets you compare the default withholding scenario against a certified treaty rate, to see the actual difference in net proceeds on a given FD interest amount.
Why FDs feel like the sharper end of this
NRO savings and NRO fixed deposit interest are taxed under the same Section 393(2) mechanism, so the underlying rule isn't actually different between the two. What usually makes it more noticeable on an FD is scale: FD interest tends to be a larger, more concentrated sum credited on a defined schedule, so the absence of any exemption threshold shows up as a bigger visible deduction than it does on the smaller, incremental interest a savings account generates.