Several terms are often mixed together. They should be understood separately.
KYC
KYC is identity verification for individual users. Eligibility, timing and process details should be checked inside official Pi systems.
Mainnet wallet access
Pi Network has introduced pathways that can allow eligible verified participants to activate a Mainnet wallet. Wallet access and Mainnet migration are not necessarily the same process.
Mainnet migration
Migration refers to moving an eligible Pioneer balance to Mainnet after applicable requirements are met.
KYB
KYB is business verification and is different from individual KYC. Pi Network states that the appropriate route can depend on the type and scale of the business; some small operators may participate using a KYC-verified individual's wallet where appropriate, while businesses that require a Pi Mainnet business wallet need to follow applicable KYB requirements.