Please let me mention something to consider that becomes apparent when you start running reports like a P&L (Profit & Loss). The Categories tab has a Type column (income, expense, transfer) and a Hide From Reports column. My post above mentioned one category [Fuel-Reimbursable (FR)] and to code the Type as Transfer. This one FR category would house both the outgoing cash (fuel purchases) and the incoming cash (paycheck reimbursements). You might consider hiding it from reports. If you do this, the FR category will not be included in your P&L. I assume the person posting might want to see a personal P&L that excludes the FR category since this basically washes out to zero over time.
It appears James has a reimbursable expense category and a reimbursable income category which he might not hide so that both are included in his P&L. This approach is fine as that might be how he wants to view his P&L. James has one income category and one expense category whereas I mention having just one transfer category.
Of course, all of this is moot unless you are running P&L reports (which I would highly recommend).
Finally, let me explain the concept behind Transfer. The easiest example is probably the moving of money from your savings account to your checking account. Money goes out of your savings account…that sounds like an expense. Money comes into your checking account…that sounds like income. Generally these two statements are true except when the money coming into your checking account is coming out of your savings account. In this case, money is exiting your left pocket and entering your right pocket. You are no poorer and are no richer. Thus, it seems odd to have an expense item and an income item that net to zero. So, with a transfer we have neither and instead have one Transfer category with a zero balance.
So, my approach is to use one Transfer category while James has one expense category and one income category. Both approaches are valid. As the accountants say, debits equal credits so we balance. The two approaches are merely two different ways to get to the same finish line and really differ only in presentation (the way the P&L will look).