question on posting non EU workers with UK visa to Schengen area

Question

I am working with a UK company whose majority shareholding is Indian. The company offers software support to client companies in Europe.

The UK company employs both EU nationals and non EU nationals under the UK visa sponsorship scheme. The 3rd party nationals can come and work in the UK for a set period, but the visa is not valid for any other part of the EU.

They now want to bring non- EU nationals to work in the UK, and potentially to work elsewhere in the EU such as Germany, France but also Switzerland etc for periods up to 2 years.

Apparently, this wouldn’t be a problem if the UK was part of the Schengen agreement, the 3rd party nationals would be able to move around, but because the UK isn’t, he’s been advised that he will need to set up a separate company in a country covered by the Schengen agreement.

does anyone have any information on the options a UK company has for posting non EU employees to work in client’s companies in the EU? is there a simple way to set something up? Or would he have to set up a company in each EU country? The problem is that they never now where the next “posting of employee” is going to be and work at quite short notice.

many thanks to anyone who can share their experience or advice on this.
Mathilde