QuickBooks Pro helpline number can be reached at 1-844-476-5438. Contacting QuickBooks customer service is possible between the hours of 6 AM and 6 PM PT, Monday through Friday. Users of QuickBooks Desktop Pro and Premier can also contact 1-844-476-5438 for help, which is available around-the-clock with varying service hours. You can contact QuickBooks Online support by phone during certain hours, by starting a conversation with an expert, or by asking questions in the community: Open from 8:00 AM to 10:00 PM on Monday through Friday and from 8:00 AM to 6:00 PM on weekends.