INSTITUTIONAL CRYPTO CUSTODY
OTC Crypto Trading for Institutions
CEX.IO Prime safekeeps your crypto on MPC custody across hot and cold storage, segregates every holding by sub-account, and settles your trades on the same account. You open sub-accounts through the API, set the withdrawal rules, and read one report.
SAFEKEEPING
Whoever holds the keys moves the funds. Prime holds key material under multi-party computation across hot and cold storage, so no single person and no single device can sign alone.
SEGREGATION
Each sub-account holds its own crypto and its own deposit addresses. An end client, a mandate, a business line or a reserve stays separate from everything beside it.
SYSTEM OF RECORD
One internal ledger posts every credit, internal transfer and withdrawal with consistent identifiers, and your statements come out of that same record.
What Prime Custody is
Prime Custody is the safekeeping layer under every CEX.IO Prime account. It stores key material with multi-party computation across hot and cold storage, issues deposit addresses per sub-account, and posts every movement to one internal ledger. The crypto you hold sits on the same account you trade and settle from.
Keys split across shares
Multi-party computation breaks key material into independent shares and signs across them. One person and one device cannot move funds alone, so a single compromised key does not put the account at risk. Prime runs hot and cold storage behind that account, and your team never builds or operates the stack itself.
A segregated holding per sub-account
Every sub-account carries its own deposit addresses for each asset and network. Incoming crypto lands in the right sub-account automatically, so you attribute a deposit to an end client, a business line or a strategy without matching it by hand. Internal transfers between sub-accounts run instantly and cost nothing.
Withdrawals under your own rules
A mandatory whitelist governs every withdrawal, so funds reach destinations you register in advance. The approval workflow sits on top, and you configure who requests a withdrawal and who signs it off. Prime records the whole chain, so your compliance team reads it back later without asking anyone to reconstruct what happened.
What you can build on Prime Custody
Clients hold their own treasury on Prime, and clients hold assets for their own users on Prime. Sub-accounts carry the separation wherever a model needs it, per end client, per mandate or per business line.
- Custody for your own end users
You create a sub-account per end user through the API or the interface, and Prime issues each one its own deposit addresses. User deposits land in the right sub-account automatically, and you reconcile per-user holdings from Prime statements. A savings app, a broker or a wallet gives its users custody-grade safekeeping and keeps the brand, the interface and the customer relationship. - Managed accounts and mandates
An asset manager runs each mandate or strategy as its own sub-account, trades each one separately against aggregated liquidity, and issues a statement per mandate to investors. One Prime relationship covers every mandate, so the manager adds a strategy without standing up new infrastructure for it. - A settlement and reporting backbone
Every operation across liquidity, settlement, payments and financing posts to one internal ledger with consistent identifiers. You pull account-level and sub-account-level statements through the interface or the API, then feed your own accounting and audit systems from one consistent record.
How custody works on CEX.IO Prime
Custody answers one question: who can sign a transaction, and under what authority. On Prime you keep that authority and CEX.IO runs the infrastructure. You open a sub-account per end user or business line, Prime issues it deposit addresses, and the internal ledger records every credit, transfer and withdrawal against that one sub-account.
You create a sub-account for each end user or business line through the Prime API or the interface. Prime Custody issues that sub-account its own deposit addresses for every asset and network you use, so incoming crypto reaches the right holding automatically and nobody on your team matches deposits by hand.
Prime keeps the crypto on institutional custody with multi-party computation across hot and cold storage. The internal ledger credits each deposit to one sub-account and keeps holdings segregated. Internal movements between sub-accounts settle instantly and cost nothing.
Your team reconciles and reports per sub-account from Prime statements through the interface or the API. The mandatory whitelist and the approval workflow govern every withdrawal, so funds leave only to addresses you register and only after the people you name approve the request.
WHY CLIENTS USE IT
- Custody-grade safekeeping on MPC across hot and cold storage, with no stack to build.
- Automatic attribution per end user through sub-account deposit addresses.
- Instant, free internal movement and clean reporting per user.
- Governance you configure through the mandatory whitelist and approval workflow.
- One counterparty for custody, liquidity, settlement and financing.
How a deposit reaches the right holding
Six steps run the same way every time, from the moment you open a sub-account to the moment your team signs off a withdrawal.
Open the sub-account
You create a sub-account per end user or business line through the Prime API or the interface.
Receive addresses
Prime Custody issues that sub-account its own deposit addresses for each asset and network you use.
Take the deposit
An end user sends crypto to that address. Network confirmations arrive and the internal ledger credits the right sub-account.
Hold under MPC
Prime keeps the crypto on MPC custody across hot and cold storage, and the holding stays segregated on its own sub-account.
Move and reconcile
Internal transfers between sub-accounts run instantly and cost nothing. You pull statements per sub-account through the interface or the API.
Withdraw under the rules
Every withdrawal runs under the mandatory whitelist and the approval workflow your team configures.
Talk to us about custody
Tell us what you hold, who you hold it for and how your team approves a withdrawal. CEX.IO scopes the account structure and the controls around your operation.
FAQ
What is institutional crypto custody?
Institutional crypto custody is the safekeeping of the private keys that control an institution's digital assets. Whoever can sign a transaction controls the assets, so custody answers the question of who moves funds and under what authority. CEX.IO Prime holds client crypto on institutional custody with multi-party computation across hot and cold storage, segregates holdings per sub-account, and gates every withdrawal behind a mandatory whitelist and an approval workflow.
How does CEX.IO Prime secure the keys?
Prime uses multi-party computation. MPC splits key material into independent shares and signs across them, so one person and one device cannot move funds alone. Prime runs hot and cold storage under the same account, and you reach both through one integration.
Can I hold assets on behalf of my own customers?
Yes. You create a sub-account per end user, and Prime issues each sub-account its own deposit addresses for every asset and network you use. Deposits land in the right sub-account automatically, holdings stay segregated, and you reconcile and report per user from Prime statements. Brokers, payment firms, fintechs and savings apps run custody for their users this way.
How do you keep my holdings separate from other clients?
Every sub-account holds its own crypto and its own deposit addresses, and the internal ledger attributes each movement to one sub-account. You separate end clients, mandates, strategies, reserves and operational funds, and each one reports on its own.
Who can approve a withdrawal?
You decide. A mandatory whitelist limits withdrawals to addresses you register in advance, and the approval workflow above it follows the separation of duties your own policy requires. Prime logs each request, each approval and each transfer, so your auditors read the chain back later.
Which assets and networks can I hold?
Prime covers 500+ assets, including BTC, ETH and stablecoins, with on-chain settlement across 60+ networks on Layer 1 and Layer 2. Fiat settles in USD, EUR and GBP over SEPA, SEPA Instant, Faster Payments and SWIFT. CEX.IO adds assets, networks and rails as client demand arrives.
How does custody connect to trading and settlement?
The crypto you hold is the crypto you trade. Custody, liquidity, settlement and financing run on one Prime account and one internal ledger, so an order executes against holdings you already keep and settles straight back into them. You reconcile one report across all of it.
How do I open a custody account, and how long does it take?
Talk to CEX.IO about the assets you hold, whether you hold them for your own customers, and the controls you need. CEX.IO configures products, assets, rails, limits and controls per client at onboarding, then issues your production keys. Your account manager confirms a schedule once the team reviews your scope and documentation.