The limitations of HubSpot's free CRM version include ^{1 2}:

• Number of contacts: 1,000,000
• Number of API calls: 40,000 per day
• Form submissions per contact: 1,000
• Custom properties: 1,000
• Values per picklist property: 1,000
• Associated contacts per company: 10,000
• Associated deals per contact or company: 10,000
• Associated activities (engagements) per contact, company, or deal: 10,000
• Only 15 minutes of calling per user per month
• No inbound calling (you can't receive calls)
• HubSpot branding on emails
• Only one sales pipeline
• No email automation