Signing up to a trading venue involves submitting documents that a self-custody wallet never asks for. The difference is not about crypto but about what kind of business is being operated.
Holding customer assets is the trigger
Financial rules in most jurisdictions attach to intermediaries: businesses that hold value for others, exchange between currencies, or transmit funds on a customer's behalf.
A centralised exchange does all three, which places it in a category that has carried identity obligations for decades regardless of the assets involved.
Software that lets a person hold their own keys does not custody anything, which is why the same requirements have not historically applied to it.
The checks serve a specific purpose
Identity verification exists so that intermediaries can tell who their customers are, monitor for patterns associated with financial crime, and respond to lawful requests.
The underlying framework predates digital assets and was built around banks, money transmitters and similar businesses.
Applying it to crypto venues was largely a matter of classification rather than new principles being invented.
Verification runs in tiers
Most platforms scale the requirements to activity, with basic details for small balances and additional documentation as limits rise.
Higher tiers commonly involve proof of address, source of funds and, for larger accounts, questions about the origin of the wealth being deposited.
The specific thresholds and documents vary considerably by jurisdiction and change over time, which is why requirements differ between platforms serving different regions.
Public chains complicate the picture
Once a withdrawal leaves a platform, the transaction is visible to anyone, and the verified identity behind the originating account is now associated with an address.
Analysis firms build on that association, mapping flows between addresses and inferring relationships from patterns of activity.
This makes public chains more traceable than cash while making the verified entry points unusually significant.
Where the boundary is being tested
Regulators have examined whether obligations should extend to interfaces, wallet software and decentralised protocols, where the traditional definition of an intermediary fits awkwardly.
Approaches differ substantially between jurisdictions, and the treatment of any particular arrangement can change as rules are revised.
Anyone whose situation depends on the answer needs advice specific to where they are, because general descriptions of the direction of travel are not a substitute for the applicable rules.