In the UK, PAYE and NI are deducted from your headline wage, but then the employer has to pay an additional NI contribution on top of that, which is what Starbu

In the UK, PAYE and NI are deducted from your headline wage, but then the employer has to pay an additional NI contribution on top of that, which is what Starbucks are presumably referring to. Employers aren't allowed to deduct this from staff wages, so instead they simply pay staff a lower wage to start with.