Token Bound Account (TBA)

A token bound account, defined by ERC-6551, gives each ERC-721 NFT its own smart contract account. The NFT stops being a passive object and can hold tokens and other NFTs and operate like a wallet, whose control belongs to whoever owns the NFT. The mechanism relies on a canonical permissionless registry, deployable to a known address on any chain, that anyone can call to create the account of an existing NFT. The registry deploys each account with CREATE2, so its address is deterministic and derivable from the implementation, the token contract, the tokenId, the chainId and a salt. It is backward compatible and does not require modifying the original ERC-721 contract.

It lets an NFT carry its own inventory: composable identity, on-chain history attached to the asset and gaming use cases where a character holds its items. As of June 2026 it is worth verifying the standard's formal status before citing it as final, since sources describe it as under review and an EIP can change status.

The reference implementation and registry were driven by Future Primitive, the standard's authors. OpenSea documents the concept and gaming and identity projects have adopted it in production and demos. ERC-6551 extends ERC-721 and therefore uses tokenURI for the identity of the NFT that controls the account. It is a smart account concept, related to ERC-4337 account abstraction though independent of it.