ExchangeRate-API is not an official rate: when not to use it

Disclosure: we run a competing API. We took ExchangeRate-API's description from its own data page and ran the comparison below on 7 November 2026.

What ExchangeRate-API actually serves

ExchangeRate-API collects rates from central banks and from commercial marketplaces. For the marketplaces, it works out a midpoint from the bid/ask spread. Then, in its own words, it uses "our own algorithm to blend all the available data into one composite indicative exchange rate."

So the number you receive was calculated by ExchangeRate-API. No central bank published it, and no market traded at it. The company is open about this: its rates are "classed as indicative midpoint rates", and it describes them as accurate enough for "price estimations in an e-commerce store, stats on a dashboard or internal reporting spreadsheets".

Same currency, same day, four answers

Here is USD/UZS on 7 November 2026. Uzbekistan's central bank publishes one official rate. The other three are what each provider returned that day.

This is one currency on one day, so don't read it as a general error rate. UZS is also thinly traded, and gaps on major pairs are usually far smaller. The point is simpler: only one of these four can be cited as Uzbekistan's official rate. On a $1,000,000 transaction, the 20 som gap to ExchangeRate-API is about 20 million som.

Where a blended rate causes problems

• VAT invoices. In the EU, Article 91(2) of the VAT Directive points to the latest selling rate on the most representative exchange market, and member states must also allow the ECB's latest rate. See our VAT invoice guide.
• Customs declarations. Customs authorities fix a rate for a period. In the UK, HMRC publishes a monthly table, and the declaration uses the rate for the month it is accepted. See our customs guide.
• Audit evidence. An auditor recomputes the conversion from the source your policy names. If that source is a proprietary blend, the rate can't be traced to a publication. See what auditors look for.
• Regulated or contractual rates. If a contract or regulator names a central bank's rate, a different figure is the wrong figure, however close it is.

Rules differ by country and change over time, so confirm yours with your adviser.

When ExchangeRate-API is fine

If nobody needs to know where the number came from, it does the job. Showing approximate prices to shoppers, a travel app, a dashboard and internal estimates are all reasonable uses. It covers more than 160 currencies and is simple to integrate.

The same limit applies to any mid-market feed, including our own live rates. Choosing a different vendor doesn't make a mid-market rate official. Choosing a published table does.

What to use instead

Use the rate from the institution your rule names, along with its publication date. You can get it from that institution's website, or from an API that passes it through unchanged. AllRatesToday serves the tables published by 123 central banks, including the Central Bank of Uzbekistan, with each publisher's own rate date. The data sources register links each table back to its source.

FAQ

Are ExchangeRate-API rates official?

No. ExchangeRate-API blends central bank and commercial market data into one composite figure, and classes the result as an indicative midpoint rate. It is not a rate published by any one institution.

Is ExchangeRate-API accurate?

For the jobs it names, yes. It says its rates are accurate enough for price estimates in an e-commerce store, dashboard stats and internal reporting spreadsheets. Accuracy is not the issue here. The issue is that a blended figure has no single publisher to cite.

Can I use ExchangeRate-API for VAT or customs?

Generally not as the rate you declare. VAT and customs rules usually name a publisher or a table, such as the ECB, a national central bank or a customs authority. Check the rule for your country, and ask your adviser if you are unsure.

Why do exchange rate APIs show different rates for the same currency?

Each provider has its own sources and method, and rates are taken at different times. The gap tends to be wider on less traded currencies. On 7 November 2026 four sources gave four different USD/UZS rates.

Are AllRatesToday's live rates official?

No. Our live rates are mid-market rates, so they have the same limit. Only our central bank and tax authority tables carry each institution's own published figures.