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Legal Updates

Tier 2 Sponsors: What is a valid Certificate of Sponsorship?

27 April 2018 #Immigration #Inward Investment

Whilst the process of assigning a Certificate of Sponsorship (CoS) is straightforward, it’s useful for sponsors to know what validates a CoS. If a CoS is not valid at the time the Tier 2 worker submits their visa application, the application will be refused resulting in delays to start date.

What is a CoS?

A CoS is a virtual document sponsors assign to workers they wish to sponsor via the Sponsorship Management System (SMS). When you are ready to assign the CoS, you will need to fill in a short online form which contains details of the person you will be sponsoring, details of their employment, the role and salary you are offering and whether you carried out and satisfied the Resident Labour Market Test (if no exemptions applied).

What is a “valid” CoS?

A CoS reference number will only be considered valid if: 

  • The sponsor assigned that reference number to the worker no more than 3 months after the CoS was allocated to the sponsor (restricted CoS);
  • The sponsor assigned the CoS to the worker no more than 3 months before the visa application was submitted;
  • The visa application is submitted no more than 3 months before the worker’s start date;
  • The CoS has not been used in a previous visa application (for example, a refused application);
  • The reference number was not withdrawn/cancelled since it was assigned;
  • The Sponsor is an A rated sponsor unless:
    • The application is for leave to remain
    • The applicant was last granted leave as a Tier 2 General worker; and
    • The applicant is applying to continue working with the same sponsor.
  • The Sponsor has paid the Immigration Skills Charge in full 

Sponsors must also ensure that the Resident Labour Market Test is still within its validity period.

Mistakes on the CoS form

On occasions where the level 1 user has made minor mistakes on a CoS (such as misspelt name or incorrect date of birth) these can be corrected by ‘adding a sponsor note’ via the SMS. This can be only done if the employee has not submitted their visa application.


Clarkslegal, specialist Immigration lawyers in London, Reading and throughout the Thames Valley.
For further information about this or any other Immigration matter please contact Clarkslegal's immigration team by email at by telephone 020 7539 8000 (London office), 0118 958 5321 (Reading office) or by completing the form on this page.
This information is for guidance purposes only and should not be regarded as a substitute for taking legal advice. Please refer to the full General Notices on our website.

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