> ## Documentation Index
> Fetch the complete documentation index at: https://docs.hedera.com/llms.txt
> Use this file to discover all available pages before exploring further.

# ERC-20 (Fungible Tokens)

The [ERC-20](https://ethereum.org/en/developers/docs/standards/tokens/erc-20/) standard defines a set of functions and events that a token contract on the Ethereum blockchain should implement. ERC-20 tokens are fungible, meaning each token is identical and can be exchanged one-to-one.

<Info>
  **Note**: `ERC-20` Token addresses refer to full Hedera Token Service (HTS) fungible token entities. These tokens can be fully managed by HTS API calls. Additionally, by utilizing [`IERC20`](https://docs.openzeppelin.com/contracts/2.x/api/token/erc721#IERC721) interfaces or system contract functions, these tokens can also be managed by smart contracts on Hedera.
</Info>

## Supported Functions

#### **From** I**nterface `ERC-20`**

<Accordion title="name">
  ```solidity theme={null}
  function name() public view returns (string)
  ```

  Returns the name of the token.
</Accordion>

<Accordion title="symbol">
  ```solidity theme={null}
  function symbol() public view returns (string)
  ```

  Returns the symbol of the token.
</Accordion>

<Accordion title="decimals">
  ```solidity theme={null}
  function decimals() public view returns (uint8)
  ```

  Returns the number of decimals the token uses.
</Accordion>

<Accordion title="totalSupply">
  ```solidity theme={null}
  function totalSupply() external view returns (uint256)
  ```

  Returns the total supply of the token.
</Accordion>

<Accordion title="balanceOf">
  ```solidity theme={null}
  function balanceOf(address account) external view returns (uint256)
  ```

  Returns of the balance of the token in the specified account. The `account` is the Hedera account ID `0.0.x` in Solidity address format or the evm address of a contract that has been created via the `CREATE2` operation.
</Accordion>

<Accordion title="allowance">
  ```solidity wrap theme={null}
  function allowance(address owner, address spender) external view returns (uint256)
  ```

  Returns the remaining number of tokens that `spender` will be allowed to spend on behalf of `owner` through `transferFrom`. This is zero by default. This value changes when `approve` or `transferFrom` are called. This works by loading the owner `FUNGIBLE_TOKEN_ALLOWANCES` from the accounts ledger and returning the allowance approved for `spender` The `owner` and `spender` address are the account IDs (0.0.num) in solidity format.
</Accordion>

<Accordion title="transfer">
  ```solidity theme={null}
  function transfer(address recipient, uint256 amount) external returns (bool)
  ```

  Transfer tokens from your account to a recipient account. The `recipient` is the Hedera account ID `0.0.x` in Solidity format or the EVM address of a contract that has been created via `CREATE2` operation.
</Accordion>

<Accordion title="transferFrom">
  ```solidity wrap theme={null}
  function transferFrom(address sender, address recipient, uint256 amount) external returns (bool)
  ```

  Moves `amount` tokens from `from` to `to` using the allowance mechanism. `amount` is then deducted from the caller's allowance.

  This works by creating a synthetic `CryptoTransferTransaction` with fungible token transfers with the `is_approval` property set to true.
</Accordion>

<Accordion title="approve">
  ```solidity theme={null}
  function approve(address spender, uint256 amount) external returns (bool)
  ```

  Sets `amount` as the allowance of `spender` over the caller's tokens.

  This works by creating a synthetic `CryptoApproveAllowanceTransaction` with payer - the account that called the precompile (the message sender property of the message frame in the EVM).

  Fires an approval event with the following signature when executed:
  event Approval(address indexed owner, address indexed spender, uint256 value);
</Accordion>

***

### **Additional References**

* [HIP-376](https://hips.hedera.com/hip/hip-376)
* [HIP-218](https://hips.hedera.com/hip/hip-218)
* [EIP-20](https://eips.ethereum.org/EIPS/eip-20)