Under the new UK immigration system, all employers in the UK need a licence to hire non-European Union workers. The application fee for the license is £300 for small business and £1000 for large companies.

You can apply The Employer Sponsorship Licence online, and it can take from 3 weeks to 4 month to get the license. According to the UK Bordr Agency website, 65% of the applications is usally decided within 4 weeks. If the job is in the shortage list, it will get processed quicker. For more, you can check the following sites:
www.ukpermits.com/employers/sponsorship-license
www.visabureau.com/uk/employer-sponsorship.aspx
www.ukba.homeoffice.gov.uk/visas-immigration/working/tier2/g