What Belongs in Each Expense Category?
Most disagreement about overhead is really disagreement about categories. Lab bills are frequently posted to supplies. Practice software and phones land in occupancy as easily as in technology. Workers’ compensation is sometimes filed with business insurance even though it is part of what the team costs.
None of that changes total operating expenses, so your overhead percentage is unaffected. It does change the breakdown, which is the part you use to decide what to look at next. Pick a convention and keep it the same every month.
Merchant and credit-card processing fees belong in professional and administrative expenses here. Recurring equipment leases, software subscriptions, service agreements and maintenance belong in equipment and technology; equipment bought outright does not.

