seems to be another labyrinth of repair companies
Zest insurance is owned by
https://find-and-update.company-information.service.gov.uk/company/05927936/officers
then if you dig around the directors they have a few companies doing this
if i were you be careful
work on a cash up front basis and charge more than normal as you have paperwork to fill in for them. insist on making a decent profit on parts too dont let any of them know what you paid for parts
so many vof these companies and it can be a pain getting paid
Dave