Certificate of Sponsorship UK: How It Works for Bangladeshi Applicants

The Certificate of Sponsorship is the document Bangladeshi professionals spend months waiting for — and then discover they have been given the wrong type. Assigning an Undefined CoS to an applicant who is applying from Dhaka rather than switching inside the UK is a technical error that causes an automatic refusal. Understanding the distinction before you accept a job offer protects both you and your employer from a costly mistake.

What the CoS Actually Is

The Certificate of Sponsorship is not a physical document you receive in the post. It is an electronic record created by your UK employer within the Home Office's Sponsorship Management System (SMS). When your employer assigns a CoS to you, they generate a reference number — typically formatted as a string of letters and numbers — that you enter into your visa application on gov.uk.

The CoS records specific details about the role: the job title, the SOC occupation code, the salary, the start date, and the sponsor's licence number. UKVI uses this information to verify that the role meets the points-based requirements before making a decision on your visa.

Your employer must hold a current, active Sponsor Licence before they can assign a CoS. If their licence is revoked after they assign you a CoS but before you receive your visa decision — or while you are in the UK — your sponsored status can be affected. Employer due diligence is not optional.

Defined vs Undefined CoS: The Critical Distinction

There are two types of CoS, and using the wrong one results in an automatic refusal.

Defined CoS is required for every applicant applying from outside the UK — including anyone applying from Dhaka, Chittagong, or Sylhet. The employer must request a Defined CoS for a specific individual and a specific role. The Home Office typically approves these within one to two working days, but may request additional information about why the role is genuinely needed and why the employer is recruiting from overseas.

Undefined CoS is for applicants already inside the UK who are switching from one visa category to another (for example, from a Student visa to a Skilled Worker visa, or extending an existing Skilled Worker permission). Employers hold an annual allocation of Undefined CoS, but they cannot use this allocation for new hires coming directly from Bangladesh.

The confusion happens when a UK employer's HR department or their immigration solicitor assigns an Undefined CoS because it is technically easier or because they have spare allocation. The applicant in Dhaka then submits the application not realising they have the wrong CoS type. The Home Office declines the application.

Before accepting a job offer, confirm in writing that your employer will assign you a Defined CoS. If they hesitate or seem unsure about the distinction, escalate to their immigration solicitor.

Verifying Your Sponsor Before You Commit

The Home Office maintains a publicly searchable Register of Licensed Sponsors. Before accepting any job offer that involves visa sponsorship, search for the company by name at gov.uk/government/publications/register-of-licensed-sponsors-workers. If the company does not appear, they cannot legally issue you a CoS, regardless of what they tell you.

This check takes two minutes and can save you months of wasted time — or worse, advance payments made to an agent under the false assumption that a legitimate offer existed.

The 90-Day Window

Once your employer has a Defined CoS assigned to you, that CoS is valid for three months. You must submit your visa application within this window. If you miss it, your employer must request a new CoS, which may require going through the Home Office approval process again.

This 90-day window is why document preparation in Bangladesh must begin before your CoS arrives, not after. The TB test, police clearance, ECCTIS verification, and bank statement period all have their own lead times. Waiting for the CoS to start gathering documents means you will almost certainly need to request an extension or miss your start date.

Immigration Skills Charge: What Your Employer Pays

Bangladeshi applicants are sometimes unaware of the financial burden their employer carries when sponsoring them. In addition to the £525 CoS assignment fee, the employer must pay the Immigration Skills Charge — increased by 32% in December 2025. For a medium or large sponsor, this is £1,320 per year of the visa duration. For a small sponsor or charitable organisation, it is £480 per year.

On a three-year visa, a large sponsor pays £3,960 in Skills Charge alone, on top of the CoS fee and any solicitor costs.

The Home Office prohibits employers from recovering these costs from the employee through salary deductions — but if deductions do occur, UKVI requires that your net pay still meets the minimum salary threshold after all deductions. Understand what deductions your employment contract allows before you sign.

If Your Sponsor Loses Their Licence

If the Home Office suspends or revokes your employer's Sponsor Licence while you are in the UK, you will typically have 60 days to find a new licensed sponsor and apply to transfer your visa. This is one reason why employer due diligence matters even after you have arrived. Periodically re-check your employer on the Register of Licensed Sponsors throughout your visa duration.

Preparing for the Full Application

The CoS is just the starting point. Once you have a valid reference number, you still need to assemble the full document package from the Bangladesh side — TB clearance, police clearance, financial evidence, and English proficiency proof.

The UK Skilled Worker Visa Guide for Bangladeshi Professionals walks through the entire process, including how to verify sponsors, the questions to ask before accepting an offer, and how to manage the 90-day CoS window around Bangladesh's bureaucratic timelines.

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