Should my small business send from a shared or dedicated IP?

For almost every small business the answer is a shared IP - the pooled address your email provider already sends from - because a dedicated IP only pays off at volumes you are unlikely to reach:

• Shared IP - your provider (Google Workspace, Microsoft 365, your newsletter tool) manages the reputation for thousands of senders at once; you inherit an established, warm reputation from day one.
• Dedicated IP - an address only you send from, which means you own the reputation entirely - good and bad - and must keep it warm with steady volume.
• The volume threshold - a dedicated IP needs roughly thousands of emails a day, every day, to stay warm; below that it goes cold and deliverability suffers.
• The real risk - a dedicated IP sending sporadically looks more suspicious to mailbox providers than a shared one, not less.

Unless you are sending tens of thousands of emails a week, stay on a shared IP and put your effort into list quality instead.