For contractors who take on different roles at different times, incomes can vary which means that saving for retirement and contributing to a pension can sometimes seem challenging. 

But, by working through an umbrella company and becoming an employee of that umbrella company a contractor has some clear advantages when it comes to saving for a pension, writes Crawford Temple, CEO of Professional Passport, the UK’s largest independent assessor of payment intermediary compliance. 

https://www.contractoruk.com/umbrella_company/salary_sacrifice_pensions_and_umbrella_companies.html