It depends on your MemberPress subscription level. You need to activate your license on each site that you install MemberPress on.
MemberPress Basic
If you have MemberPress Basic, then no. MemberPress Basic can only be used on one site.
MemberPress Plus and MemberPress Pro
If you have MemberPress Plus or Pro, then yes. You can use MemberPress Plus and Pro on the number of site activations allowed. Below are some factors to consider before using MemberPress on multiple sites.
WordPress Multisite vs. Separate Websites
MemberPress does not officially support WordPress Multisite at this time, but some customers have had success getting it to work. Some functions and add-ons may not work correctly or as expected on a WordPress Multisite setup.
MemberPress can run independently on seperate websites. If you need to integrate, or share membership data between separate sites, you will need to use Zapier or a custom implementation to sync the data between sites.
Stripe
Stripe's terms of service requires a separate Stripe account for each legal entity. So if you sites are seperate businesses then you will need seperate Stripe accounts. You can setup multiple Stripe accounts under a single email address. For more information see Stripe's article on multiple accounts.
If your sites all operate under the same legal entity you MUST use Stripe Elements on your sites. Stripe Check DOES NOT support multiple websites.
PayPal
PayPal standard requires the use of IPN in PayPal. PayPal can only have one IPN url setup at a time. So if you need to use PayPal on multiple websites we recommend having seperate PayPal accounts.
Syncing Data
If you need MemberPress to share data between you sites, you will need to set up a custom integration that updates the information across sites. We recommend using our official Zapier integration for this. You can also use our Developer Tools add-on to create a custom integration.