Royal Monetary Authority of Bhutan Exchange Rate API: Official BTN Rates as JSON

The Royal Monetary Authority of Bhutan publishes the official exchange rates that accounting, tax, and customs rules in Bhutan reference — published official rates, not moving market prices. This guide shows how to pull them as JSON: via a REST endpoint or the zero-dependency rma-bhutan-exchange-rate npm package.

What the RMA publishes

• Daily telegraphic-transfer buying and selling rates for 12 currencies — AUD, CAD, DKK, EUR, HKD, JPY, NOK, GBP, SGD, SEK, CHF and USD, in BTN per unit.
• The 1:1 rupee peg — the ngultrum is fixed to the Indian rupee, so the table tracks the rupee's moves against the majors.
• History back to May 2024 in our API, queryable by exact date or as a series.
• The bank's own publication date on every response; weekends and Bhutanese holidays resolve to the most recent published table and are flagged.

Bhutan's currency moves in lockstep with the Indian rupee, but Bhutanese banks, importers and the tax administration still need the ngultrum figure as the RMA itself prints it — and this table is that official record.

Why official rates, not market rates

A live mid-market feed answers "what is USD/BTN trading at right now?" — the right tool for checkouts and dashboards. But accountants, auditors, and tax authorities ask a different question: "which rate were you required to use for this date?" That answer comes from the Royal Monetary Authority of Bhutan's published rates, and it never changes after publication.

Get the latest rates (REST)

curl "https://allratestoday.com/api/v1/central-bank/rma/latest" \
  -H "Authorization: Bearer YOUR_API_KEY"

The response is the bank's most recent published data — every rate and the publication date. The latest rates are available on every plan, including the free tier (300 requests/month, no credit card).

The npm SDK

npm install rma-bhutan-exchange-rate

import { getRate, getLatestRates } from 'rma-bhutan-exchange-rate';

// One pair at the official RMA rate
const pair = await getRate('USD', 'BTN', { apiKey: 'art_live_...' });
console.log(pair.rate, pair.rate_date);

// The bank's full published table
const table = await getLatestRates({ apiKey: 'art_live_...' });
console.log(table.rate_date, table.rates.length);

Zero dependencies, TypeScript types included, and it runs anywhere fetch exists — Node 18+, Bun, Deno, and edge runtimes.

Historical rates for an invoice date

import { getRatesForDate, getHistory } from 'rma-bhutan-exchange-rate';

// The official rates for an invoice date — non-publication days return
// the most recent published date, flagged via published_on_requested_date.
const day = await getRatesForDate('2026-06-30', { apiKey: 'art_live_...' });

// Time series for one pair
const series = await getHistory(
  { source: 'USD', target: 'BTN', from: '2026-01-01' },
  { apiKey: 'art_live_...' }
);

Historical dates and time series need a paid plan; the latest rates stay free.

Published vs derived pairs

If the RMA does not print a pair directly, the API resolves it from the bank's published rates — an inverse, or a cross rate via BTN — and flags it derived: true with the method used. Official and computed values are never silently mixed, which is exactly the distinction an auditor will ask about.

The series since May 2024

Our archive starts where the RMA's own online archive does, in May 2024 — every business day's TT buying and selling table since, stored with its publication date. For a filing that needs the official rate on a given date, one call returns it.

FAQ

Does the Royal Monetary Authority of Bhutan have an official exchange rate API?

The RMA publishes its official rates on its own site, and AllRatesToday serves the same published rates as clean JSON via REST or the rma-bhutan-exchange-rate npm package. The latest table is free.

How often do Royal Monetary Authority of Bhutan rates update?

Once per business day, as telegraphic-transfer buying and selling rates for 12 currencies. Because of the 1:1 peg the dollar rate mirrors the rupee's; every API response carries the RMA's publication date.

Can I get the RMA rate for a past date, like an invoice date?

Yes. The /central-bank/rma/rates-for-date endpoint returns the official rates for any archived date. Non-publication days resolve to the most recent published date and are flagged, so your audit trail stays honest. Historical dates require a paid plan; latest rates are free.