Your Interactive Guide to prepare for a Certificate of Sponsorship (CoS) Request
Requesting a Certificate of Sponsorship (CoS), for new hires or even renewing the old ones, is no longer a simple administrative task. The Home Office is applying intense scrutiny, and rejection rates are high.
We have done an intense analysis of common rejection letters that sponsor licence holders receive. We have discovered the reasons why most sponsors fail before they even submit the request. Most commontly, they are unable to provide the specific, detailed evidence the Home Office requires to prove a vacancy is genuine and that all sponsor duties are being met.
This guide outlines the critical systems and evidence you must have in place before you request a CoS. Using a professional HR system, such as the one offered by IRS HR, is essential for managing the level of compliance and record-keeping now required.
This guide is not a substitute for legal advice. Always refer to the latest guidance on the GOV.UK website. We recommend consulting an immigration solicitor for further help. Last updated based on guidance available as of October 2025
Five Common Reasons for CoS Rejection
Based on a review of Home Office certificates of assigned rejection letters, applications are overwhelmingly refused for these 5 avoidable reasons.
Failure to Prove a "Genuine Vacancy"
This is the most common reason. The sponsor cannot provide evidence of current, guaranteed work for the requested migrant.
Incomplete or Incorrect Hierarchy Charts
The provided chart is missing key information, such as vacant posts or details of current migrant workers.
Insufficient Job Descriptions
The duties listed in the CoS application are too brief or do not match the selected SOC (Standard Occupational Classification) code.
Failure to Respond to Information Requests
The sponsor does not reply to a Home Office email requesting further evidence within the (often short) deadline.
Incorrect Supporting Documents
The sponsor provides a "draft" or "template" employment contract when asked for contracts of existing sponsored staff.
This guide is a direct action plan to prevent these failures.
Your 3-step CoS-Request Action Plan
Do not attempt to request a CoS until you have completed the following steps and compiled the required evidence. Navigate through the steps using the tabs below.
Step 1: Calculate how many vacant hours of work you need for each CoS
The Home Office needs to see that you have enough hours able to request CoS, not just the hope of future work. You must be able to demonstrate your need with simple math.
Interactive Vacancy Calculator
Provable Vacant Hours
0
Justifiable New Hires (at 37.5h/wk)
0
Action: Gather all client/service contracts and use this calculation to determine your exact, provable number of vacant hours. If you cannot do this, you are not ready to request a CoS.
Step 2: Prepare Your HR Documentation
This is where a dedicated HR system like IRS HR becomes vital. You must have these documents ready to send at a moment's notice.
The Hierarchy Chart
This is a key point of failure. Your chart must be current and detailed.
Detailed Job Descriptions
Step 3: Manage Your Communication Channels
This simple step is often overlooked and leads to automatic rejections.
Monitor Your Email
The Home Office will send any Request for Further Information (RFI) to the Key Contact's email address.
Check the SMS Portal
Final Recommendation
The evidence in provided rejection letters makes it clear that the Home Office is operating a strict, evidence-based system. You will not be granted a CoS based on projections, "tenders," or incomplete records.
Before you spend time and money on a CoS application that may be refused, invest in solidifying your internal HR systems. A service like IRS HR is designed to manage compliance, maintain records, and ensure you have the correct documentation (like hierarchy charts and contracts) readily available.
By preparing your evidence before you apply, you directly address the primary reasons for failure and significantly increase your chances of a successful CoS allocation.
Evidence and Demonstrate with IRS HR
Avoid the 5-day-response anxiety with IRS HR. With IRS HR, you automate your HR sponsor duties and processes. IRS HR is a secure cloud-based platform that can easily evidence and demonstrate to the Home Office that you have processes, documentation, and system in place to request the certificates of sposnorship you need.
The above guide is not a substitute for legal advice. Always refer to the latest guidance on the GOV.UK website. We recommend consulting an immigration solicitor for further help. Last updated based on guidance available as of October 2025