The calculator says outsourcing is cheaper. Is that the best choice?
No, this covers the cost side only. Minimum volumes, evening surcharges, knowledge transfer, and whether the bureau works inside your own inbox all sit outside the math. Use the sum as a filter, then test quality: first response time and the share of conversations without repeat contact.
What if the bureau rate is below my internal hourly cost?
Then the bureau bills each occupied hour below your own hourly cost. In-house still pays at least your coverage hours, and every hour above that at your own rate, so the bureau wins at every volume and the break-even stays empty. If your internal cost is the lower one, the break-even marks the volume where running it in-house flips over.
Which input should come from my own data?
All of it, ideally: conversations per month and duration from your inbox reporting, your occupancy from your own history (or an estimate between 75% and 85%), the opening hours you actually want covered, and rates from real bureau quotes. Do not substitute industry averages when your own history exists.