TCO (Total Cost of Ownership)
The full multi-year cost of a support tool, counting implementation, integration, admin, and training on top of the subscription line.
TCO = subscription/licences + implementation + integrations + training + internal admin labour + migration/exit costs (over a fixed 3-5 year horizon)TCO is the sum of everything a support platform costs you across its useful life, not just the per-seat price on the order form. That price is the most visible number in a vendor comparison and usually the smallest slice of the real bill. The rest hides in implementation, data migration, integration build and upkeep, admin and configuration labour, training, and the eventual cost of leaving.
The rule of thumb is stark. In a Gartner study cited for help desk and customer service software, acquisition accounts for only about 30% of five-year TCO — the other roughly 70% is ongoing configuration, integration maintenance, administration, upgrades, and support (Giva). The single most under-counted line is your own people: the reps pulled off the floor to test and train, and the admin who quietly becomes a half-time employee of the tool.
Used well, TCO forces an apples-to-apples comparison — ask every vendor for a three-to-five-year all-in estimate, not a sticker price, because a cheap licence with an expensive integration and a manual migration can lose to a pricier tool that runs itself. Model the exit cost too; the day you want to leave is the day you learn what lock-in was worth.
What it hides: TCO is a spreadsheet built on assumptions, and you can make almost any tool win by choosing the time horizon, which internal labour you count, and how optimistic the adoption curve is. It also systematically under-weights switching cost and vendor lock-in, which don't show up until years later — long after the purchase decision it was supposed to inform.