Best Exchange Rate API for Australia in 2026: 8 Compared for AUD Rates, RBA and ATO Use

Australian businesses price against the US dollar and report to the ATO in Australian dollars. A product needs a live AUD rate; the tax return needs foreign income translated at the rate prevailing at the time of the transaction or at an average. Since 2020 the ATO has used Reserve Bank of Australia rates for its own tables, which makes the RBA series the natural reference.

This comparison looks at eight exchange rate APIs from the point of view of a team in Australia. Free-tier limits and prices were read from each provider's own pricing page on 10 November 2026; they change often, so confirm before you commit.

What a team in Australia needs from an exchange rate API

• Live AUD pairs for pricing, checkout and travel products.
• Reserve Bank of Australia daily rates, struck around 4.00 pm Sydney time.
• The rate by date and averages for translating foreign income and expenses.
• Financial-year handling: the Australian income year runs 1 July to 30 June, so calendar-year averages are no use.

Quick comparison

The Australian rates and what they are for

• Reserve Bank of Australia rates. Published each business day for the US dollar and around 18 other currencies, plus the trade-weighted index, based on rates around 4.00 pm Sydney time. The RBA describes them as indications of market value.
• ATO rule. All foreign income, deductions and foreign tax paid must be translated to Australian dollars, at the exchange rate prevailing at the time of a transaction or at an average rate.
• ATO tables. The ATO states that from 1 January 2020 it has used exchange rates from the Reserve Bank of Australia, and that anyone who needs daily rates should refer to the RBA. It publishes monthly tables for each income year. For currencies it does not list, any reasonable externally sourced rate may be used.
• Averages. An average may cover a period of up to 12 months and must be a reasonable approximation of the spot rates in that period.

The point for choosing an API: a market mid-rate and an official table are different products. A market rate is right for showing a customer a price. It is not the figure a tax form or an auditor asks for.

The eight providers

1. AllRatesToday

Best for: teams that need both kinds of rate. Mid-market rates for 160+ currencies refresh every 60 seconds on every plan, on any base currency, over HTTPS. The same key serves the official tables of 123 central banks and 6 tax authorities, each with the publisher's own date. For Australia that means: Reserve Bank of Australia daily rates. Output is JSON, CSV, XML or Excel from the same endpoints, with SDKs for JavaScript, Python, PHP, Go and Rust and an MCP server for AI agents. Paid plans start at €4.99 a month; dated tables and history are on paid plans.

2. Frankfurter

Best for: projects that only need official fixings and want them free. Frankfurter is open source, needs no key and has no monthly cap. It now aggregates 111 central banks and official sources. For Australia its source list covers: Reserve Bank of Australia. It serves official fixings, not a live market rate, and it is a free service with no paid tier or support contract.

3. ExchangeRate-API

Best for: dashboards and reports that need volume and can live with one update a day. The free plan gives 1,500 requests a month with daily updates; the Pro plan is $10 a month for 30,000 requests with hourly updates. Rates are a blended market figure, not a named institution's table.

4. Open Exchange Rates

Best for: teams that want a long-established vendor and work from a US dollar base. The free plan gives 1,000 requests a month with hourly updates on a USD base; other base currencies start with the $12 a month plan.

5. CurrencyAPI

Best for: small private projects. The free plan gives 300 requests a month with daily updates and is for private use only; paid plans start at $12.99 a month.

6. Fixer

Best for: teams already on the apilayer marketplace. The free plan gives 100 calls a month with hourly updates for non-commercial use, and base-currency switching is listed only on paid plans, which start at $14.99 a month.

7. currencylayer

Best for: the same apilayer stack with a dollar source. The free plan gives 100 calls a month with daily updates for non-commercial use; paid plans start at $14.99 a month.

8. XE Currency Data

Best for: banks and large companies that need a recognised vendor on an annual contract. There is a trial but no free plan; the entry plan is $599 a year for 10,000 requests a month with daily rates.

Try it for AUD

# live mid-market rate
curl "https://allratestoday.com/api/v1/rates?source=AUD&target=USD" \
  -H "Authorization: Bearer YOUR_API_KEY"

# Reserve Bank of Australia, latest table
curl "https://allratestoday.com/api/open/central-bank/rba"

# an income-year series, 1 July to 30 June
curl "https://allratestoday.com/api/v1/central-bank/rba/history?symbol=USD&from=2025-07-01&to=2026-06-30" \
  -H "Authorization: Bearer YOUR_API_KEY"

The first call needs a free API key. The official table responses carry the table's own date, so you can show which publication a figure came from.

Which one should you pick?

FAQ

What is the best exchange rate API for Australia in 2026?

For live AUD rates plus Reserve Bank of Australia daily rates on one key, AllRatesToday. For RBA fixings free and without a key, Frankfurter. For the largest free quota of daily market rates, ExchangeRate-API.

Which exchange rates does the ATO use?

The ATO states that from 1 January 2020 it has used exchange rates from the Reserve Bank of Australia, and refers people who need daily rates to the RBA.

Can I use an average exchange rate for my Australian tax return?

Yes, within limits. The ATO allows conversion at the rate prevailing at the time of a transaction or at an average rate, where the average covers no more than 12 months and is a reasonable approximation of the spot rates.

When does the RBA publish exchange rates?

Each business day, excluding New South Wales public and bank holidays, based on rates around 4.00 pm Sydney time.