Basically, cash cards are a bit different from credit cards. You can’t use them if there is no money in a bank account. Besides, the primary account holder is your employer. So, it can boost his credit score, not yours. I would highly recommend you carefully re-read the agreement you signed. You might get into some unpredicted financial situations and be responsible for your employer's actions. Moreover, sometimes it is better to consult with some trusted experts in this field before signing anything and giving your social number. When I have some questions, I usually get a consultation on https://taxfyle.com/business-incorporation-services I think sometimes it is worth paying for a piece of advice before you sign anything.