🪪 Soulbound Token SBT
A non-transferable token that lives permanently in one wallet and proves who you are or what you've earned — a credential, achievement, or identity, rather than something you own to sell.
🪪 The simple version — a credential, not a collectible
Think of the things that prove something about you in the real world: a university diploma, a driver's license, a vaccination record. You can show them, but selling them makes no sense, because they only mean something tied to you. A soulbound token is the on-chain version of exactly that. Once it's issued to your wallet, it's bound there for good: you can't sell it, gift it, or move it. Because it can never be traded on a market, an SBT has no price tag — its value is the trust or proof it carries, not money.
👻 Where the idea came from
The concept was laid out in May 2022 in a paper called Decentralized Society: Finding Web3's Soul by Ethereum co-founder Vitalik Buterin, lawyer Puja Ohlhaver, and economist E. Glen Weyl. The name borrows from the game World of Warcraft, where a "soulbound" item binds to one player and can never be traded. In this vision, a wallet that collects SBTs is called a "Soul" — picture an identity passport, with each credential stamped into it. One person can hold several Souls for different parts of life (work, school, community).
🆚 Soulbound token vs regular NFT
| 🪪 Soulbound Token | 🖼️ Regular NFT | |
|---|---|---|
| Can you sell it? | No — non-transferable | Yes — tradable on a market |
| What it represents | Who you are / what you earned | Something you own |
| Has a market price? | No | Yes |
| Real-world cousin | Diploma, license, ID | Baseball card, artwork |
📌 Both are built with token technology on a blockchain. The single difference that matters: an SBT can't change hands.
🛠️ What people use them for
- 🎓 Credentials — education, work history, certifications you can prove without a middleman
- 🧑🤝🧑 Proof you're a real person — passing KYC or blocking bots and fake accounts (sybil resistance)
- 🗳️ Fairer voting — a DAO can give one verified person one vote, instead of "more money = more votes"
- 🎟️ Attendance & reputation — proof you showed up to an event, or a track record used for lending decisions
🚨 Things beginners should know
- 🔒 Not private by default — anyone who knows your wallet address can see the SBTs bound to it
- 🔑 Lost keys, lost credentials — if you lose access to your wallet, the SBTs go with it; "social recovery" fixes are still experimental
- 🔥 The issuer can revoke — whoever gave you the token can often burn it to cancel a fake or expired credential
- 🌱 Still early — much of the grand vision (on-chain reputation, credit, identity) is a work in progress, not a finished system
🌍 A real example you can meet today
The Binance Account Bound (BAB) token is one of the first large-scale SBTs. Issued on BNB Chain, it's a non-transferable proof that a user finished Binance's KYC identity check. Because it can't be bought or moved, projects use it to hand rewards to verified humans rather than armies of bots. Many of the SBT standards themselves are being built on Ethereum.
❓ FAQ
- Is a soulbound token just a kind of NFT?
- It uses the same token technology, but it behaves differently. A normal NFT is something you own and can sell, like a tradable card. An SBT is stuck to your wallet forever — you can show it but you can never sell, gift, or move it, like a diploma with your name on it.
- Can I ever lose or remove a soulbound token?
- You can't move or sell it yourself. The issuer who gave it to you can often burn (destroy) it to revoke a credential — for example to cancel a fake or expired one. And if you lose access to your wallet's keys, the token is gone with it, because it lives only in that one wallet.
- Are soulbound tokens private?
- Not by default. Anyone who knows your wallet address can usually see every SBT bound to it, which means your credentials and affiliations are public. That is a real privacy concern, and ways to hide or selectively reveal them are still being worked out.