Mentors are automatically added to My Teach First based on the information held on salesforce. Please check the following:

1. Look up the mentor on salesforce
2. Check which email address they have set as their preferred email, this is their login email
3. Check they have the relevant Mentor TF Support Role
4. Check they have the correct contact relationships (Advisor) active for their mentor role ie. The start date is in the past and the end date is in the future. 
5. If above is correct advise Mentor they may be using the incorrect password, you can direct them to the reset password link here: https://connect2.teachfirst.org.uk/connect/password

If any of these are missing the mentor will not have access to My Teach First. If the start date is in the future: their account will be activated on their start date. 

If any of these are missing the mentor will not have access to My Teach First Please ensure you arrange to get the contact relationships corrected. 

If the above information is all set up correctly, and the mentor still cannot get access then raise a support ticket for further information.