You will need a minimum of four references and you can use managers, peers, colleagues, clients, teachers etcetera.
The problem is, if you are using an employment agency they will only accept references from two of your previous managers or supervisors, and they must be recent employers, not older ones.
They won't accept mobile telephone or social email addresses such as Google or Hotmail so you can only use work related email addresses which stipulates where your manager works.
And the system cannot send a text message to a landline telephone number either.
Response from Checkster:
04 September 2020 at 09:11
Hello, thanks so much for sharing your thoughts! At this time, we can confirm invitations may be sent by text message or by email (including Google, Hotmail, etc). If you have any questions about this, please feel free to connect with us at [email protected] and we'd be happy to help you out!