ERC-20

ERC-20 defines a common set of functions every token implements: balance lookup, transfer, approve and transfer-from, plus events that announce each transfer. Because every token follows it, wallets and exchanges can support a new token by knowing its contract address and decimals.

What to know as a receiver:

• An ERC-20 transfer is a call to the token's contract, paid for in ETH as gas. An address holding only tokens can't move them.
• Transfers are detected from the contract's Transfer events, not from the address's ETH balance.
• The standard is followed loosely by some tokens. USDT on Ethereum, for example, doesn't return a value from transfer as the standard says it should, which naive integrations have tripped over.

The same standard is used on other EVM networks, sometimes under a local name such as BEP-20 on BNB Chain.

On Valtu

Valtu supports ERC-20 tokens on Ethereum, Polygon, Base and Lisk. Each coin page lists the contract Valtu accepts, and a gas wallet can pay the ETH or POL that token payouts and sweeps need.