Token Standards: A Reference

Entry last verified June 2026.

The main standards on EVM chains

Standard	Purpose	Key property
Fungible token standard	Interchangeable units	Balances and approvals
Non-fungible standard	Unique items	Individual ownership records
Multi-token standard	Both in one contract	Batch operations
Permit extension	Gasless approvals	Approval by signature rather than transaction

Why the standards matter

Interoperability. Any wallet, exchange or contract can handle any token following a standard without custom code. This is why a new token works everywhere immediately.

Predictable behaviour. The functions and events are defined, which is what lets explorers display transfers and wallets show balances.

Where they cause problems

Tokens with non-standard behaviour. Some implement the interface while behaving differently: taking a fee on transfer, rebasing balances, or blocking transfers from specific addresses.

Contracts expecting standard behaviour break when interacting with these, which has caused real losses in protocols that did not anticipate them.

The permit extension. Approval by signature is convenient and it is also the basis of signature phishing, because signing a message feels less consequential than sending a transaction while carrying identical authority.

Approval semantics. The standard approval is an allowance that does not expire. That design decision is the root of the largest category of wallet drains.

The transfer-with-fee case

A token that deducts a percentage on every transfer means the amount received differs from the amount sent.

Applications that assume the two are equal fail, and users encounter unexpected shortfalls. Checking whether a token has a transfer fee before using it in any protocol is worth the two minutes.

For a holder

Most of this is invisible. Standard tokens behave as expected in standard wallets.

The two things worth knowing are that approvals do not expire, and that a signature can carry the same authority as a transaction.

Both are addressed by the same practice: a separate wallet for connecting to applications, holding a small balance, with long-term holdings in a wallet that has never connected to anything and a working balance at a regulated European platform where no signature applies at all.