Welcome to the forum. Are you the business owner or the bookkeeper ?. The reason I ask is for two reasons
1) Under the ICB motto, and as one of the forums moderators, we do not encourage unqualified bookkeepers to provide services to the clients. It is clear that you do not seem to be aware of some of the basic rules of bookkeeping and payroll services- self-employed. I would strongly recommend that you complete some qualifications whether with us or some bookkeeping body. You may already be a student but under the code of conducts for the ICB bookkeepers who are not qualified or have the confidence or not allowed to provide bookkeeping services to clients
2) About the question, I will pretend that I am HM Inspector here. The fact that you referred to the person as a member of staff raises very loud questions. So, I am going to say I would put 50:50 bet they are an actual employee even if they are part-time.
If the individual is self-employed, he would include his expenses in his invoice and charge vat if he is vat register. HMRC have announced that they are coming down heavily in the next lot of inspections on employers who deliberately treat someone as self-employed to get out of paying PAYE and NI and Auto-enrolment. As a company, you are required by law to full fill this requirement. One of the rules is they must supply their equipment, set their hours and can send another person to do the work.
A self-employed person does not get subsistence. So there should never be any subsistence ever recorded for a self-employed individual if you do then they are an employee.
Edited at 23 Oct 2016 01:33 PM GMT