What does self-custody mean in Bitcoin?
Correct answer
Answer B: You control and protect the keys yourself.
Quick explanation
With self-custody, there is no provider that can simply reset your access. Backing up and protecting the keys is therefore your own responsibility.
Detailed explanation
Self-custody does not mean bitcoin physically sit on a device. What matters is who controls the keys that can authorize a valid spend. In a simple wallet, one person may control the required key alone. Multisig can involve several self-selected keys and locations. In both cases, no external custodian can decide withdrawals alone.
Someone holding bitcoin on an exchange or with a custody service typically has a claim against that provider. The service controls the technical keys and may face security problems, solvency issues, legal requirements or withdrawal freezes. This does not mean every custodian is untrustworthy. Custody may be simpler or more appropriate for some users. Self-custody does not remove risk but shifts it: backup loss, theft, user error and an unclear emergency plan fall more heavily on the user. A good system must fit the user's knowledge, amount and situation. More technical control is useful only when the security process is genuinely understood and managed.
Key control means technical spending power: whoever can sign validly can spend bitcoin. It does not automatically prove lawful ownership; theft, custody agreements, trusts or inheritance can separate technical control from legal entitlement.
Example or everyday application
On an exchange, the user submits a withdrawal request and the exchange signs. In self-custody, the user's own wallet signs, and nobody can centrally reset a forgotten backup. A custodian holds a key for a club. They can technically sign but do not automatically own the funds personally.
Common misconception
The slogan Not your keys is sometimes understood as a blanket claim that every custodian is fraudulent. Self-custody describes technical key control and changes counterparty risk; it does not prove every custodian is a fraud. Misconception: blockchain control settles every ownership question. In fact, technical and legal levels must be distinguished.
What the sources support
Bitcoin wallet documentation explains control of private keys. MiCA describes custody by crypto-asset service providers. Together the sources clarify the distinction: self-custody means controlling your own keys rather than relying on a custodian.