Cryptocurrency Codes — BTC, ETH, USDT & More
Reference for common cryptocurrency codes and their relationship to ISO 4217. Covers Bitcoin (BTC), Ethereum (ETH), stablecoins, and ticker conventions used in exchanges and APIs.
Detailed Explanation
Cryptocurrency Code Conventions
While ISO 4217 governs fiat currency codes, cryptocurrency codes follow their own conventions that have evolved organically through exchanges, protocols, and community usage.
Major Cryptocurrency Codes
| Code | Name | Decimals | Notes |
|---|---|---|---|
| BTC | Bitcoin | 8 (satoshis) | The original cryptocurrency |
| ETH | Ethereum | 18 (wei) | Smart contract platform |
| USDT | Tether | 6 | USD-pegged stablecoin |
| USDC | USD Coin | 6 | USD-pegged stablecoin |
| XRP | Ripple | 6 | Payment network |
| SOL | Solana | 9 (lamports) | High-throughput blockchain |
| ADA | Cardano | 6 (lovelace) | Proof-of-stake blockchain |
| DOGE | Dogecoin | 8 | Meme-originated currency |
| LTC | Litecoin | 8 | Bitcoin fork |
| DOT | Polkadot | 10 (planck) | Multi-chain protocol |
Decimal Places and Precision
Cryptocurrency decimal places are significantly different from fiat currencies:
- Bitcoin: 8 decimals (1 BTC = 100,000,000 satoshis)
- Ethereum: 18 decimals (1 ETH = 10^18 wei)
- Most ERC-20 tokens: 6 or 18 decimals
This means standard float or double types are insufficient for cryptocurrency amounts. You must use:
- BigInt / BigNumber libraries in JavaScript
decimal.Decimalin PythonBigDecimalin Java/Kotlin
ISO 4217 Relationship
Cryptocurrency codes are not part of ISO 4217. There was a proposal to assign XBT as Bitcoin's ISO 4217 code (following the X-prefix convention for non-country currencies), but it was never officially adopted. BTC remains the de facto standard.
Some stablecoins mirror fiat codes with prefixes or suffixes (USDT, USDC, BUSD), which can cause confusion in systems that expect only ISO 4217 codes.
API Integration
Most exchange APIs use uppercase ticker symbols: BTC, ETH, SOL. Trading pairs are formatted as BTC/USD, ETH/BTC, or BTC-USD depending on the exchange.
Use Case
Developers building cryptocurrency exchanges, wallets, DeFi applications, or payment gateways that support both fiat and crypto need to handle the drastically different decimal precision requirements and code conventions. A system that treats BTC like USD (2 decimals) will lose precision for micro-transactions, while treating ETH amounts as regular numbers will cause overflow issues.