Commingling

Commingling is the combining of funds or assets from different sources or owners in a shared account, wallet or pool. It occurs in traditional financial accounts as well as crypto custody. Moving assets between wallets controlled by one person does not, by itself, show that different owners' assets have been combined.

How Pooled Custody Works

An exchange may hold several customers' deposits together in a shared wallet while maintaining a separate balance for each customer in its internal ledger. The wallet holds the pooled assets, while the ledger tracks each customer's balance. Identifying a customer's entitlement does not necessarily require assigning particular coins to that customer.

When a deposit, withdrawal or trade changes a customer's balance, the corresponding records must be updated. Reconciliation checks whether customer balance records agree with the assets and transactions recorded across the relevant accounts or wallets, allowing for items such as pending transfers. Commingling can simplify administration and potentially reduce operating costs, but it does not remove the need to account for each participant's share.

Ownership Records and Asset Separation

Pooling assets belonging to several customers is different from mixing customer assets with a custodian's own operating funds. Separate customer balances can coexist with pooled custody, but an internal ledger alone does not establish that customer assets are held separately from business assets. The custody arrangement and agreements matter alongside the accounting records.

Commingling is not inherently theft, money laundering or unlawful. Whether a particular arrangement is permitted depends on the applicable rules and agreements. Poor allocation records can nevertheless create accounting failures and ownership disputes, especially when determining how much each participant is owed. Clear balance records and appropriate separation address related but distinct risks.

Security and Transaction Traceability

Where pooled assets share compromised keys or custody controls, one incident can affect multiple customers and potentially the entire affected pool. Commingling alone does not establish a higher probability of hacking, and a breach of one wallet does not necessarily affect every asset held by an exchange. The scope of exposure depends on which assets rely on the compromised keys or controls.

Combining illicit and legitimate assets can complicate checks on the origin of funds and anti-money laundering (AML) monitoring. Ordinary pooled custody is not synonymous with services designed to obscure transaction paths, and pooling does not automatically erase transaction trails or provide anonymity. Blockchain records can support tracing, but an on-chain transfer does not, by itself, establish beneficial ownership or identify the customer credited in an internal ledger.

Practical Controls and Their Limits

Oversight of commingling requires clear per-owner records, regular reconciliation and appropriate separation of customer and business assets. Per-owner records show each participant's recorded entitlement; reconciliation tests those records against actual holdings and transactions. Separation helps keep customer holdings distinct from funds used to run the business. These measures cannot substitute for controls over who can move assets or access custody keys.

Smart contracts can automate agreed allocation rules for a shared pool, but their outputs depend on the programmed rules and how they are implemented. Automation does not guarantee fair distributions, correct ownership records, protection from fraud or secure custody. Neither blockchain visibility nor automation replaces sound ownership records, custody security or applicable compliance controls.