What are minor units in ISO 4217?

Minor units are the number of decimal places a currency uses. Most currencies use 2 (cents), some use 0 (such as the Japanese yen) and a few Gulf dinars use 3. Payment systems use this to store amounts as integers.

Why do currencies have both a letter code and a number?

The three-letter code (such as USD) is human-readable, while the three-digit numeric code is script-independent and useful in datasets where letters could be ambiguous. Both are defined by ISO 4217.

Why does the Japanese yen have 0 minor units?

The yen has no commonly used sub-unit, so its minor-unit count is 0 and amounts are whole numbers. Payment systems must store ¥1000 as 1000, not 100000, which is why knowing the minor units matters.

How does the first letter of a currency code work?

ISO 4217 alphabetic codes are usually the two-letter country code plus the first letter of the currency name — for example US + Dollar = USD, GB + Pound = GBP. This makes most codes easy to recognise.

Which currencies use 3 decimal places?

A few Gulf currencies such as the Bahraini dinar (BHD), Kuwaiti dinar (KWD) and Omani rial (OMR) divide into 1000 fils, so they have 3 minor units rather than the usual 2.

Is anything uploaded when I search?

No. The currency list is bundled with the page and all filtering runs locally in your browser.

What is the ISO Currency Codes Reference?

Free ISO 4217 currency code reference — search three-letter codes, numeric codes and minor-unit decimals for every major currency. Runs entirely in your browser. It runs free in your browser on Gera Tools, with nothing uploaded.

ISO Currency Codes Reference

Name: ISO Currency Codes Reference
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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ISO 4217 currency codes

Look up any currency by its ISO 4217 three-letter code, numeric code or name. This standard is essential for payments, invoicing, accounting and FX systems, where the code and decimal precision must be exactly right to avoid mis-stated amounts.

How it works

The currency list ships with the page, so every lookup is instant and runs locally. Type a code, name or number and the table filters to matching rows. Each row shows the alphabetic code, numeric code, currency name and minor units — the number of decimal places, which payment processors use to store amounts as integers.

Code	Numeric	Minor units	Smallest unit
USD	840	2	cent
EUR	978	2	cent
JPY	392	0	(none)
KWD	414	3	fils

Why minor units matter in payment systems

Payment APIs — Stripe, Adyen, PayPal, and others — require amounts as integers in the currency’s minor unit to avoid floating-point errors. The rule is:

amount_in_minor_units = decimal_amount × 10^(minor_units)

So EUR 19.99 is submitted as 1999, USD 100.00 as 10000, and JPY 1500 as 1500 (since JPY has 0 minor units, the yen amount is used directly). Getting this wrong means charging a customer 100 times too much or too little — a mistake that payment processors see often enough that most will reject obviously wrong amounts, but not always.

The three currencies where this trips people up most often:

JPY (Japanese Yen): 0 minor units. ¥1500 = integer 1500. Do not multiply by 100.
KWD/BHD/OMR (Gulf Dinars): 3 minor units. KWD 1.000 = integer 1000. Multiply by 1000, not 100.
CLF (Chilean Unidad de Fomento): 4 minor units — a rarely encountered edge case but real.

How ISO 4217 alphabetic codes are structured

Most three-letter codes follow a pattern: the first two letters match the ISO 3166-1 alpha-2 country code, and the third letter names the currency. For example:

USD: US (United States) + D (Dollar)
GBP: GB (Great Britain) + P (Pound)
EUR: EU (European Union) — an exception, since EU is not a standard ISO 3166 country code
XAU: X prefix currencies are non-country codes (gold, SDR, Bitcoin test cases)

The X prefix is reserved for currencies not tied to a single country — gold (XAU), silver (XAG), the IMF Special Drawing Right (XDR), and test transactions (XTS).

Codes that require a second lookup

Some scenarios produce confusion worth knowing:

EUR vs national euro-zone codes: the old Deutsche Mark (DEM), French Franc (FRF), and others are withdrawn codes, not synonyms for EUR. A payment system should use EUR for any euro-zone transaction today.
GBP vs GIP, JEP, GGP: the pound sterling (GBP) is the code for England, Scotland, Wales, and Northern Ireland. Gibraltar, Jersey, and Guernsey have their own pound variants, but they are officially at par with GBP and share the numeric code 826.

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