As you're considering which Office 365 subscription will best meet your needs, keep in mind the differences in how you work with domains in a small businesses (P) subscription compared to an enterprise (E) or midsize business subscription. Understanding the details of how the subscription types work with custom domains can help you choose the right subscription for your needs, and help you add and manage your domain more easily in Office 365.

For example, consider the following differences:

• All subscriptions allow you to continue to host your current website outside of Office 365, but with a “P” subscription, you’ll need to take a few additional steps to get this working correctly.
• With a “P” subscription, you’ll typically manage DNS records in Office 365 after adding your domain, while with an “E” or "M" subscription, you continue to manage the records with your current DNS hosting provider.
• With a “P” subscription, you can add second-level domains, such as contoso.com but you cannot add subdomains, such as partners.contoso.com. With an “E” or "M" subscription, you can have multiple subdomains: for example, www.contoso.com, www.partners.contoso.com, www.partners.contoso.marketing.com, and so on.

For more details about the differences, see information comparing domain management in different Office 365 subscriptions in this topic.