If you have imported a large amount of users in Office 365, the first task you will need to tackle is assigning them all a licence. This is a two step process:
1. Set the Usage location
2. Assign the licence
Use the following commands to achieve this:
Get-MsolAccountSku
Get-MsolUser -UnlicencedUsersOnly | Set-Msoluser -UseageLocation “GB”
Get-MsolUser -UnlicencedUsersOnly | Set-MsolUserLicense -UserPrincipalName [email protected] -AddLicenses “Contoso:ENTERPRISEPACK”