Cost-to-serve is the only mobility metric that matters

Ask a mobility programme how it’s doing and you’ll usually get two numbers: how many devices it runs, and what the carrier bill was. Both are real. Neither tells you whether the programme is run well. Device count measures size, not health. The carrier total goes up when you hire and down when you shrink — it moves with headcount, not with management quality.

The number that actually answers the question is cost-to-serve: the fully loaded monthly cost of keeping one employee productively connected. It’s the metric a CFO can trend quarter over quarter, compare against benchmarks, and hold someone accountable for. And most organisations have never calculated it.

What goes in the number — and the trap in the denominator

Cost-to-serve is simple to state: everything it costs to run the mobile estate in a month, divided by the devices actively serving someone.

The numerator is bigger than the carrier invoice. It includes airtime and data, hardware amortisation and accessories, helpdesk and support effort, the admin time spent on procurement, joiners-movers-leavers and invoice wrangling, and the logistics of getting devices out, back, wiped and redeployed. Industry research puts the internal administration burden alone at roughly one IT full-time equivalent per 250 employees — a cost that never appears on any carrier bill.

The denominator is where programmes flatter themselves. Divide by total lines and the number looks healthy, because industry data consistently finds 18–22% of enterprise mobile lines are inactive — billed, but serving nobody. Divide by active devices and the truth surfaces: every zombie line you’re paying for is loaded onto the cost of the people you actually serve. The first honest thing cost-to-serve does is make inactive lines impossible to ignore.

The carrier invoice is the smaller half of the problem

Carrier-only benchmarks put enterprise mobile at $30–$80 per device per month, with well-governed estates at the lower end. But the gap between a well-run and a badly-run programme is wider than that range suggests, because the waste hides off-invoice: over-provisioned plans (2025 research found employees consume an average of 6.6 GB a month against plans of 50–200 GB — under 7% of what’s bought), support tickets that take three teams to close, devices that leave with employees and never come back, and spreadsheets reconciling all of it.

That’s why chasing the carrier rate alone plateaus quickly. A renegotiation moves the airtime line once; governance moves the whole number every month.

Device count tells you how big your estate is. Cost-to-serve tells you whether it’s run well — and keeps telling you, every month.

What actually moves it

• Line governance. Detect and disconnect inactive lines continuously, not at contract renewal. This is usually the fastest single reduction available.
• Right-sized plans. Pool data and match tiers to measured usage rather than provisioning for the loudest hypothetical.
• One front door for support. A single helpdesk and catalogue for the full lifecycle — order, swap, repair, leaver — collapses the internal shuffling that quietly dominates cost.
• Closed-loop logistics. Devices recovered, sanitised and redeployed are devices you don’t buy twice; residual value recovered is cost clawed back. This is where mobility and reverse logistics stop being separate programmes.
• Measure it monthly, own it singly. A metric nobody owns is a report; a metric one person owns with a monthly cadence is a programme. It’s also the honest basis for outcome-based commercials — a partner paid against cost-to-serve is a partner whose incentives point the same way yours do.

The compounding effect is real: our largest mobility engagement — 45,000 devices across 14 markets, consolidated under a single data model and contract — reduced cost-to-serve by 38%. The mechanics weren’t exotic; they were the five levers above, applied continuously instead of annually. The Schindler case study has the detail.

Start with the number you can defend

You can’t manage a number you compute once a year in a spreadsheet. Cost-to-serve only works as a live metric — carrier data, inventory, tickets and logistics in one reconciled model, so the figure is current and its movements are explainable line by line. That’s the reason it’s a first-class number in Veroxos rather than a slide produced for QBRs.

See where your estate sits against sector figures in the 2026 TEM Benchmark Report, get a first estimate in 60 seconds with the ROI calculator, or put your own device-estate export in front of us in a 30-minute demo.

See the platform behind the post.