If the sponsor is sponsoring you for license/regulatory coverage in the US, then the client legally belongs to them, this means, the KYC data lies with them. Unlike Europe and (UK, pre-Brexit), the PII (Personally Identifiable Information) was passport-able. That is not applicable in the United States. This implies that customers signed up in the United States, their KYC information belongs to the PLH (Principal License Holder), unless you are an Agent, in which case, you ‘may’ have the right to KYC the customer, but the PLH will always retain the right to have KYC information.
If you interact with a customer outside the United States (in-bound or out-bound) transaction flow, then the PLH has the right to ask you for KYC data to know the counterparty of the transaction.