Claiming a business in ChatGPT is free. The Business Hub needs a ChatGPT account, and a free account works. Reading this guide needs nothing at all.
Business Agents, an optional agent that talks to customers for you, are in beta and only open to eligible ecommerce and online-service businesses in the United States. Verification alone doesn't guarantee agent access.
Shopify merchants can connect their store from Business Hub or from the Shopify admin.
A free ChatGPT account is enough for the Business Hub; we loaded it on one. Businesses can also sponsor their Business Agent as a ChatGPT Ads destination. That's advertising, a separate option from claiming.