# Custody (custodial / self-custody)

Holding crypto-assets or their private keys for someone else; self-custody means the owner controls the keys.

Canonical: https://achivx.org/glossary/custody/
Updated: 2026-11-01

Custody is holding crypto-assets, or the means of access to them, on behalf of someone else. MiCA defines custody and administration for clients as the safekeeping or controlling of clients' crypto-assets or the means of access to them, where applicable private cryptographic keys. Brazil's central bank defines a self-custodied wallet as one whose owner controls the private key and can move it without a virtual-asset service provider. The GENIUS Act's custody rules exclude firms that only provide hardware or software for customers' own custody.

## What the sources say

| Source | Quote | Link |
|---|---|---|
| MiCA Art. 3(1)(17): custody and administration | "‘providing custody and administration of crypto-assets on behalf of clients’ means the safekeeping or controlling, on behalf of clients, of crypto-assets or of the means of access to such crypto-assets, where applicable in the form of private cryptographic keys;" | [publications.europa.eu](https://publications.europa.eu/resource/cellar/01d55833-0660-11ee-b12e-01aa75ed71a1.0006.03/DOC_1) |
| BCB Resolution 521: self-custodied wallet | "II - carteira autocustodiada é aquela cujo proprietário detém o controle da respectiva chave privada, sendo capaz de movimentá-la sem necessidade de participação de prestadora de serviços de ativos virtuais;" | [bcb.gov.br](https://www.bcb.gov.br/estabilidadefinanceira/exibenormativo?tipo=Resolu%C3%A7%C3%A3o%20BCB&numero=521) |
| GENIUS Act sec. 10(e): exclusion for self-custody tools | "(e) Exclusion.--The requirements of this section shall not apply to any person solely on the basis that such person engages in the business of providing hardware or software to facilitate a customer's own custody or safekeeping of the customer's payment stablecoins or private keys." | [govinfo.gov](https://www.govinfo.gov/content/pkg/PLAW-119publ27/html/PLAW-119publ27.htm) |
| BCB Resolution 520: virtual-asset custodians | "Art. 8º Os custodiantes de ativos virtuais têm por objeto social a custódia de ativos virtuais." | [bcb.gov.br](https://www.bcb.gov.br/estabilidadefinanceira/exibenormativo?tipo=Resolu%C3%A7%C3%A3o%20BCB&numero=520) |
| MiCA ES Art. 3(1)(17): Spanish term | "«custodia y administración de criptoactivos por cuenta de clientes»: la guarda o el control, por cuenta de clientes, de criptoactivos" | [publications.europa.eu](https://publications.europa.eu/resource/cellar/01d55833-0660-11ee-b12e-01aa75ed71a1.0023.03/DOC_1) |
| Türkiye Law 7518: crypto-asset custody service | "Kripto varlık saklama hizmeti: Platform müşterilerinin kripto varlıklarının veya bu varlıklara ilişkin cüzdandan transfer hakkı sağlayan özel anahtarların saklanmasını, yönetimini veya Kurulca belirlenecek diğer saklama hizmetlerini," | [resmigazete.gov.tr](https://www.resmigazete.gov.tr/eskiler/2024/07/20240702-1.htm) |

## Related terms

- [CASP (MiCA)](/glossary/casp/)
- [VASP](/glossary/vasp/)
- [Issuer failure / insolvency](/glossary/issuer-failure/)
- [Proof of reserves](/glossary/proof-of-reserves/)

## See also

- Review: [revain.org/wallets/ledger-nano-x/](https://revain.org/wallets/ledger-nano-x/)
- Review: [revain.org/wallets/bitgo/](https://revain.org/wallets/bitgo/)

Checked against the sources on 2026-11-01.

## revain.org
- https://revain.org/wallets/ledger-nano-x/
- https://revain.org/wallets/bitgo/

## Sources
- https://publications.europa.eu/resource/cellar/01d55833-0660-11ee-b12e-01aa75ed71a1.0006.03/DOC_1
- https://www.bcb.gov.br/estabilidadefinanceira/exibenormativo?tipo=Resolu%C3%A7%C3%A3o%20BCB&numero=521
- https://www.govinfo.gov/content/pkg/PLAW-119publ27/html/PLAW-119publ27.htm
- https://www.bcb.gov.br/estabilidadefinanceira/exibenormativo?tipo=Resolu%C3%A7%C3%A3o%20BCB&numero=520
- https://publications.europa.eu/resource/cellar/01d55833-0660-11ee-b12e-01aa75ed71a1.0023.03/DOC_1
- https://www.resmigazete.gov.tr/eskiler/2024/07/20240702-1.htm