An exchange rate is usually quoted in terms of the number of units of one currency that can be exchanged for one unit of another currency – e.g., in the form: 1.2290 EUR/USD. In this example, the US$ is referred to as the “quote currency” (price currency, payment currency) and the Euro is the “base currency” (unit currency, transaction currency).
There is a market convention that determines which is the base currency and which is the term currency. In many parts of the world, the order is: EUR – GBP – AUD – NZD – USD – others. Accordingly, a conversion from EUR to AUD, EUR is the base currency, AUD is the term currency and the exchange rate indicates how many Australian dollars would be paid or received for 1 Euro. Cyprus and Malta which were quoted as the base to the USD and others were recently removed from this list when they joined the Euro.
In some areas of Europe and in the non-professional market in the UK, EUR and GBP are reversed so that GBP is quoted as the base currency to the euro. In order to determine which is the base currency where both currencies are not listed (i.e. both are “other”), market convention is to use the base currency which gives an exchange rate greater than 1.000. This avoids rounding issues and exchange rates being quoted to more than 4 decimal places. There are some exceptions to this rule e.g. the Japanese often quote their currency as the base to other currencies.
Quotes using a country’s home currency as the price currency (e.g., EUR 0.735342 = USD 1.00 in the euro zone) are known as direct quotation or price quotation (from that country’s perspective) and are used by most countries. Quotes using a country’s home currency as the unit currency (e.g., EUR 1.00 = USD 1.35991 in the euro zone) are known as indirect quotation or quantity quotation and are used in British newspapers and are also common in Australia, New Zealand and the eurozone.
Using direct quotation, if the home currency is strengthening (i.e., appreciating, or becoming more valuable) then the exchange rate number decreases. Conversely if the foreign currency is strengthening, the exchange rate number increases and the home currency is depreciating.
Market convention from the early 1980s to 2006 was that most currency pairs were quoted to 4 decimal places for spot transactions and up to 6 decimal places for forward outrights or swaps. (The fourth decimal place is usually referred to as a “pip”). An exception to this was exchange rates with a value of less than 1.000 which were usually quoted to 5 or 6 decimal places. Although there is no fixed rule, exchange rates with a value greater than around 20 were usually quoted to 3 decimal places and currencies with a value greater than 80 were quoted to 2 decimal places. Currencies over 5000 were usually quoted with no decimal places (e.g. the former Turkish Lira). e.g. (GBPOMR : 0.765432 – EURUSD : 1.5877 – GBPBEF : 58.234 – EURJPY : 165.29). In other words, quotes are given with 5 digits. Where rates are below 1, quotes frequently include 5 decimal places.
In 2005 Barclays Capital broke with convention by offering spot exchange rates with 5 or 6 decimal places on their electronic dealing platform. The contraction of spreads (the difference between the bid and offer rates) arguably necessitated finer pricing and gave the banks the ability to try and win transaction on multibank trading platforms where all banks may otherwise have been quoting the same price. A number of other banks have now followed this system.