Danmarks Nationalbank Exchange Rate API: Official DKK Rates as JSON

The Danmarks Nationalbank publishes the official exchange rates that accounting, tax, and customs rules in Denmark 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 danmarks-nationalbank-exchange-rate npm package.

What the Danmarks Nationalbank publishes

• ~33 currencies against the krone — the official daily table published around 16:00 Copenhagen time.
• History back to 2016 — queryable by exact date or as a time series.
• The bank's own publication date on every response, so a rate is always citable.
• No gaps to trip over — weekends and Danish holidays resolve to the most recent published rates and are flagged explicitly.

The USD/DKK rate anchors the table for pricing and reporting, while the EUR/DKK series documents the fixed-rate policy itself — the krone has been pegged to the euro in ERM II since 1999, held within a narrow band around 7.46.

Why official rates, not market rates

A live mid-market feed answers "what is USD/DKK 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 Danmarks Nationalbank's published rates, and it never changes after publication.

Get the latest rates (REST)

curl "https://allratestoday.com/api/v1/central-bank/dnb/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 danmarks-nationalbank-exchange-rate

import { getRate, getLatestRates } from 'danmarks-nationalbank-exchange-rate';

// One pair at the official Danmarks Nationalbank rate
const pair = await getRate('USD', 'DKK', { 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 'danmarks-nationalbank-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: 'DKK', 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 Danmarks Nationalbank does not print a pair directly, the API resolves it from the bank's published rates — an inverse, or a cross rate via DKK — 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.

A decade of krone history

The series runs from 2016 and shows two currencies in one: an EUR/DKK line that barely moves — the ERM II peg doing its job — and a USD/DKK line that swings with the dollar cycle, from the 6.2s to above 7.6 in 2022. For invoice-date lookups and audits, the Nationalbank's print is the official record.

FAQ

Does the Danmarks Nationalbank have an official exchange rate API?

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

How often do Danmarks Nationalbank rates update?

Once per business day, around 16:00 Copenhagen time. These are published official rates, not moving market prices — every API response carries the publication date so you can cite it.

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

Yes. The /central-bank/dnb/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.