What's the difference between Claude Pro, Max, Teams, and Enterprise in terms of data security and cost for using it with client data?

Pro (~$20/month) does not use conversations for model training, retains data for a limited period, and encrypts data in transit and at rest — this was considered acceptable for bookkeeping use as long as training is turned off in settings. Max (personal plan, $100 or $200/month tier) offers similar protections; one participant on Max was told by Claude that data submitted stays contained within their group but sending it to Claude does introduce some risk, comparable to other tools like Adobe or QuickBooks that also have AI features looking at data. Enterprise is considered the most secure (SOC-type compliance) but requires purchasing a minimum of five licenses even if you don't need that many, and it's billed based on usage rather than a fixed fee, which can get expensive quickly — seen as unfair for small businesses/solo firms. Teams was also mentioned as an option for firms wanting stronger data security without going full Enterprise.