Prospective employees and students can commence employment or studies while their visa applications are outstanding. 

If you are the sponsoring employer of a visa applicant who has submitted their application for leave to remain under Tier 2 or Tier 5 and is waiting for a decision, you may allow the employee to start work before their visa is granted. To benefit from this adjustment to the requirements, you must have assigned a Certificate of Sponsorship (“CoS”) to the employee, they must have submitted their application before their current visa expired and the role they will be employed in must be the same as the one on their CoS.

The guidance reminds employers that reporting responsibilities for an employee start from the date you have assigned them a CoS, not from the date that their application is granted. The employer will not be able to use the Sponsor Management System to report information to the Home Office until the application is granted. We would recommend that you retain any relevant information, as required by the Home Office guidance for sponsors, and keep your own robust records.

If the employee’s application is refused you must cease sponsorship and terminate employment.

If you are the sponsor of a student who is waiting for their Tier 4 visa application to be decided they may commence their studies if you have assigned the student a Confirmation of Acceptance of Studies (CAS), the student submitted their application before their current visa expired and has shown you evidence of this and the course they start is the same as the one listed on their CAS.

If required, the student will need a valid Academic Technology Approval Scheme (ATAS) certificate.

As with sponsored employment, reporting responsibilities start from the date that you issue the CAS, not from the date that the application is granted.

If the student’s application is refused you must cease sponsorship and terminate their studies.

Source: https://www.gov.uk/guidance/coronavirus-covid-19-advice-for-tier-2-4-and-5-sponsors