What Are ERC-20 Tokens? A Practical Guide for 2026

ERC-20 is a technical standard for tokens created on Ethereum. It sets common rules that let wallets, exchanges and apps recognise and handle those tokens in a consistent way. The token itself is managed by a smart contract: software deployed on the blockchain that tracks balances and applies the token’s rules.

ERC-20 tokens are fungible. In ordinary use, one unit of a token is interchangeable with another unit of the same token, much like one dollar is interchangeable with another dollar. That differs from a non-fungible token, where individual items are distinct.

The standard does not say that a token is trustworthy, valuable or backed by anything. It mainly provides a shared interface. A token can comply with that interface and still have an unreliable issuer, little liquidity, restrictive contract rules or no useful purpose. Treat the label as a compatibility clue, not a quality rating.

A token contract keeps track of balances and provides functions that other software can use. Common ERC-20 functions include balanceOf to check a wallet’s balance, transfer to send tokens, and totalSupply to report the token’s supply. The approve and transferFrom functions let a user authorise another address or app to move tokens within an allowance.

The standard also defines events, such as Transfer, that wallets and blockchain explorers can use to detect activity. A token may show a name, ticker symbol and number of decimal places in a wallet, but these labels are not unique identifiers. Different contracts can use the same name or ticker.

In practice, the contract address is the key identifier. A wallet or app reads the contract to display a token balance and prepare transactions. The standard makes basic compatibility easier, but individual contracts can include extra features or limitations. Check the specific token contract and its terms rather than assuming every ERC-20 works in exactly the same way.

ETH is Ethereum’s native asset. It is used to pay for network activity and is not an ERC-20 token. ERC-20 tokens are separate assets whose balances are recorded by their own smart contracts. That means you can hold tokens in an Ethereum wallet without holding the tokens’ issuer’s private keys, but you still need control of your wallet to authorise transactions.

ERC-20 also differs from ERC-721, a widely used standard for non-fungible tokens, where each token is distinct. Other token standards support different features and use cases.

Network names matter. ERC-20 specifically describes Ethereum’s token standard, although compatible token contracts are also common on Ethereum Virtual Machine (EVM) networks. The same asset name can appear on multiple networks, but a token on one network is not automatically the same on another. Before receiving or sending, confirm that both the sending service and receiving wallet support the exact network. Sending a token using an unsupported network can make it inaccessible.

ERC-20 tokens can represent many things: a project’s utility or governance token, a stablecoin designed to track a currency, or a token used in an on-chain application. The ERC-20 standard itself does not define what the token represents or guarantee a holder’s rights. Those depend on the project, contract and any applicable terms.

Tokens can be held in a compatible wallet, transferred between compatible addresses, or traded where a supported market exists. A decentralised exchange such as Uniswap can let users swap tokens from a wallet, while a wallet tool such as MetaMask Swap can route a trade. These services do not remove the need to verify the token, network, quote and transaction details.

Some lending applications also accept selected ERC-20 assets as deposits or collateral. Acceptance is application-specific: a token being ERC-20 does not mean every platform supports it. Before using a token in an app, check its contract address, network, liquidity, any fees and the risks of the app itself.

If you want to receive or send an ERC-20 token, use this sequence:

1. Confirm the network. Make sure the sender, recipient and wallet all support the same network.
2. Verify the token contract. Use the project’s official materials to check the contract address. Do not rely on a ticker or search result alone.
3. Check the destination address. Confirm the full address and that it can receive the token on that network.
4. Review the transaction. Check the token, amount, network and estimated fee in your wallet before signing.
5. Wait for confirmation. Use the wallet’s transaction status, and avoid sending again just because an update is slow.

For a first transfer or a large amount, a small test transfer can help catch a wrong address or network. It costs an extra transaction fee, so consider that trade-off. If you use an exchange, follow its deposit instructions exactly; some services require a particular network or additional reference details. Never share your recovery phrase to receive tokens.

An Ethereum transaction usually requires a network fee, called gas, paid in ETH on Ethereum mainnet. The fee compensates the network for processing the transaction; it is separate from the amount of tokens being sent. A token transfer, a swap and a contract approval can each require a transaction, so an app may ask you to pay more than once while you use it.

The final cost varies with network demand and the work a transaction requires. A swap may also include a decentralised-exchange fee, and its quoted price can reflect slippage or other execution effects. Centralised exchanges may charge their own trading or withdrawal fees, with terms that differ by service and asset.

Before confirming, check the wallet’s gas estimate, the amount you will receive in a swap and any separate platform charge. On an EVM network other than Ethereum mainnet, you generally need that network’s gas asset, not necessarily ETH. Do not assume a low displayed token price means the transaction itself is cheap.

The main risks are sending to the wrong network or address, interacting with a counterfeit token, and approving an app to spend more tokens than you intend. A confirmed transfer is generally not reversible. A token’s contract can also contain rules or weaknesses that affect transfers, and a token can lose value or become difficult to trade.

When an app requests approval, read which token and spending amount it asks for. Some approvals allow spending up to a set amount; others may be unlimited. Grant only what you are comfortable with, and review or revoke old allowances using a reputable wallet feature or tool. Revoking an allowance requires a transaction and may cost gas.

Avoid these common mistakes:

• Trusting a ticker or token name instead of checking the contract address.
• Sending on a network the recipient does not support.
• Signing a transaction without understanding its approval or amount.
• Sharing your recovery phrase or following unsolicited support messages.
• Assuming ERC-20 compliance proves a token is safe, audited or redeemable.

Keep your wallet software current and confirm details before signing.