Except for their non-transferability, soulbound tokens function similarly to NFTs, which is why Ethereum creator Vitalik Buterin refers to them as non-transferable NFTs. They are non-fungible, which means they cannot be exchanged, and each token is unique and non-transferable.

Souls have the ability to issue self-certified SBTs to themselves. However, a common occurrence is when other Souls or SBT creators send an SBT to the address of another Soul. On the blockchain, the SBT, its issuer, and Soul's address can all be publicly verified. As a result, anyone can easily track or prove a Soul's trust circles.