The same thing happened to me. I was working as a courier for CitySprint. They said we were self-employed and we didn’t have the right to minimum wage of holiday pay.
With my union, the IWGB, we took them to tribunal.
We also brought cases against Excel, Addison Lee, and eCourier as well. They were saying we were self-employed and weren’t entitled to any of these rights.
They were just wrong to say we were independent contractors. In law we are ‘integrated into the organisation’, so we’re classified as ‘workers’ – so we’re entitled to the national minimum wage, paid annual leave, protection from discrimination.
The lawyers did most of it to be honest. I just put my name on the bit of paper.
Anyway, we won it in the beginning of January 2017. The judge did a very good job exposing all the rubbish that CitySprint were arguing.