This is actually TERRIBLE advice.

To the IRS, and to an accountant, there is a difference between:

* a normal expense and a reimbursable expense

* income (revenue) and reimbursement

When properly documented, reimbursable expenses and reimbursements are completely non-taxable.

As an example, please see IRS Publication 463, under self-employed expense reimbursements. https://www.irs.gov/publications/p463#en_US_2023_publink10009985

The "vendor" recording those, does NOT record them according to the normal tax category. The "client" does!

Thus, these literally are pass-through costs (done by the "vendor" for the convenience of the "client") and do not change your company total revenue, or P&L.

ALL of this must be properly documented, or the IRS *will* treat it as normal revenue and expense.

AND it's even trickier if this is an employer/employee relationship. Then you need an "Accountable" reimbursement plan.