21 essential terms in plain English. CoS, BRP, ILR, ISL, going rate, SOC codes — every acronym you'll meet in a UK Skilled Worker application.
Sponsor licence in good standing
The default rating assigned to UK sponsors who comply with their sponsor duties. A-rated sponsors can issue Certificates of Sponsorship (CoS) without restriction. The Home Office downgrades to B-rated if compliance issues arise.
Sponsor licence on remedial action plan
Assigned when the Home Office finds compliance gaps during an audit. B-rated sponsors cannot issue new CoS until they pass an action-plan review and pay an additional £1,476 fee. Many regain A-rating within 3 months.
Biometric Residence Permit
Physical card issued to non-UK nationals on visas longer than 6 months. Phased out from 31 December 2024 in favour of eVisa (digital status). Existing BRPs remain valid until expiry.
Certificate of Sponsorship
A unique 8-character reference number issued by a sponsor employer to a prospective worker. The CoS confirms the sponsor will provide the role described and is required before the worker applies for their visa. Defined CoS (named individual, sponsor pays £239 immigration skills charge per year) and Undefined CoS (allocation-based, used for in-country switching).
Pre-allocated CoS for an out-of-country worker
Issued for someone applying from outside the UK. Sponsors must request these case-by-case from the Home Office and the request is usually granted within 1 working day.
Sponsor allocation for in-country switching
Sponsors receive an annual allocation of Undefined CoS to assign to workers already in the UK switching from another visa or extending. Allocation refreshed each April; can request increases mid-year.
Occupation-specific minimum salary
Floor salary for a given SOC code, set by the ONS Annual Survey of Hours and Earnings (ASHE) at the 25th percentile, then uplifted 50% per HC 590 (April 2024). The applied salary must meet whichever is higher: the going rate or the general threshold (£41,700).
Skilled Worker variant for healthcare roles
Subset of Skilled Worker for SOC codes in healthcare (nurses, doctors, paramedics, social care workers from 11 March 2024 with restrictions). Lower visa fees, exemption from the Immigration Health Surcharge, and access to ISL discount. Salary floor £29,000 (lower than the general £41,700) for many roles.
Immigration Health Surcharge
£1,035/year (£776/year for students, under-18s, and Youth Mobility) paid upfront for the full visa duration. Grants NHS access. Exempt: Health and Care Worker visa holders.
Indefinite Leave to Remain
Permanent UK settlement, achievable after 5 years on the Skilled Worker route (3 years on Global Talent / Innovator Founder). Applicant must pass Life in the UK test, English language test (B1 minimum), continuous residence requirements (no >180 days outside UK in any 12-month rolling window), and pay £2,885 application fee.
ISL — discounted salary tier replacing the Shortage Occupation List
Effective 4 April 2024 (HC 590). 20% discount on the general threshold and going rate for listed occupations. Currently includes care workers, fishing trawler crew, civil engineers and others. Reviewed annually by the Migration Advisory Committee. Replaced the Shortage Occupation List which gave 80%.
ISC — sponsor levy paid per year of CoS
£1,000/year for medium and large sponsors; £364/year for small sponsors (under 50 staff or under £10.2m turnover). Charity-route sponsors and Switch CoS are exempt. Applies to Skilled Worker and Senior or Specialist Worker routes. Paid by the sponsor, never recoupable from the worker.
Reduced threshold for under-26s and recent qualifiers
A 30% discount on the general threshold for workers under 26 at the time of application, or within 3 years of obtaining their qualifying degree. Currently £33,380 (vs. £41,700 general). Applies for the first 4 years of Skilled Worker stay only.
Points-Based System
UK immigration framework (post-2008) under which all work routes operate. Skilled Worker requires 70 points: 50 mandatory (job offer from licensed sponsor + appropriate skill level + English) + 20 tradeable (salary, PhD, ISL, new entrant).
Employer obligation before hiring
UK employers must verify a worker's immigration status before employment starts. Acceptable evidence: passport + share code (online) or original BRP. Failure to check = up to £60,000 civil penalty per illegal worker (raised from £20,000 on 13 February 2024).
Primary UK work visa route
Replaced Tier 2 (General) on 1 December 2020. Up to 5 years per CoS, extendable. Leads to ILR. Salary minimum £41,700 general or £33,380 ISL. Must be sponsored by a licensed UK employer holding a Worker route licence.
Standard Occupational Classification — 4-digit job code
ONS taxonomy of UK occupations. Each Skilled Worker visa application is mapped to a SOC code, which determines the going rate and ISL eligibility. The current scheme is SOC 2020 (some sources still reference SOC 2010).
Ongoing compliance obligations on licensed sponsors
Includes record-keeping (passport copies, contact details, attendance), reporting (within 10 working days for absences >10 days, contract changes, salary changes), cooperation with Home Office audits, and not employing workers outside their CoS scope. Non-compliance = licence downgrade or revocation.
Home Office authorisation to employ visa workers
A UK employer must hold a licence on the Worker route (or Temporary Worker route) before they can sponsor a visa application. Application fee £1,579 medium/large or £574 small/charity. Decision within 8 weeks (or 10 working days with priority service for £500). Valid 4 years.
Changing visa route from inside the UK
Most work routes allow switching without leaving the UK (Student → Skilled Worker, Graduate → Skilled Worker, Skilled Worker → Skilled Worker for new employer). Requires Undefined CoS from the new sponsor, not a Defined CoS.
Points substituting for salary headroom
Awarded for: PhD relevant to job (10 points), STEM PhD (20), ISL job (20), New Entrant (20), Health and Care Worker (20). Combine with mandatory 50 to reach 70. Tradeable points can lower the salary requirement to as low as £33,380 — but the floor is absolute.
SponsorshipJobs (2026). UK Work-Visa Glossary. https://sponsorshipjobs.io/uk-immigration-glossary.