The verdict in three sentences
With 70 shared vehicles and a paper diary, an organisation of 800 staff uses on average 35 % of its fleet, because phantom bookings and cars kept "just in case" block the pool. A custom booking app costs 18,000 to 45,000 EUR excluding VAT depending on whether you add connected key cabinets and directory integration. By lifting utilisation towards 60 %, it lets you hand back 10 to 15 vehicles, far more than its cost in the first year.
Why the paper diary is so expensive
In Berlin, a pool car on a full-service lease costs 450 to 650 EUR per month excluding VAT (lease, insurance, maintenance), before fuel or charging. Across 70 vehicles, the fleet weighs between 380,000 and 545,000 EUR a year. The problem is rarely the number of trips, it is organisation: whole-day bookings for a two-hour trip, keys kept in one office, no reliable mileage history, no way to know which car is actually free.
| Indicator | Paper diary or spreadsheet | Dedicated app |
|---|---|---|
| Average utilisation | 30 to 40 % | 55 to 65 % |
| No-show bookings | 15 to 25 % | 3 to 6 % (automatic release) |
| Fleet admin time | 0.5 to 1 FTE | 0.1 to 0.2 FTE |
| Logbook entry | Paper, often incomplete | Mobile, mileage and damage photos |
| Cost tracking per department | Impossible or yearly | Monthly, per directorate |
| Key handover | Facilities office | Connected cabinet or badge |
| Data for the mobility plan | None | Trips, distances, powertrains |
The switch to electric raises the stakes: an EV must be recharged between trips, and the app must account for remaining range and available chargers on site.
What the app includes and what it costs
The typical scope for 800 staff and 70 vehicles across three or four Berlin sites includes a web and mobile app, a directory connection (Azure AD or LDAP) for login, priority rules by department, and a back office for the fleet manager.
| Module | Content | 2026 cost excl. VAT |
|---|---|---|
| Web and mobile booking | Calendar, filters, rules, notifications | 8,000 to 15,000 EUR |
| Directory and roles | SSO, approvers, delegations | 2,000 to 5,000 EUR |
| Digital logbook | Mileage, fuel, damage with photo | 3,000 to 7,000 EUR |
| Cost tracking and dashboards | Cost per department, utilisation, accounting export | 3,000 to 8,000 EUR |
| EV management | Range, charger booking | 2,000 to 5,000 EUR |
| Connected keys integration (option) | Key cabinet API or in-car telematics box | 3,000 to 10,000 EUR |
| Total project | Depending on options | 18,000 to 45,000 EUR |
Hardware is not included: a connected key cabinet costs 4,000 to 9,000 EUR for 20 to 40 keys, an in-car telematics box 15 to 35 EUR per vehicle per month. Application maintenance usually represents 15 to 20 % of the project cost per year. Delivery takes 3 to 5 months, pilot included. In Germany, involve the works council (Betriebsrat) early, since any system able to monitor employees falls under co-determination.
The calculation that decides the project
The reasoning is in vehicles handed back. If the organisation makes the same number of trips with utilisation rising from 35 % to 60 %, it theoretically needs about 41 vehicles instead of 70. In practice you keep a margin for peaks and special vehicles, and hand back 10 to 15.
| Scenario | Vehicles handed back | Annual saving excl. VAT | Payback |
|---|---|---|---|
| Cautious | 8 | 43,000 to 62,000 EUR | 4 to 10 months |
| Median | 12 | 65,000 to 94,000 EUR | 3 to 7 months |
| Ambitious | 15 | 81,000 to 117,000 EUR | 2 to 6 months |
| Fleet manager time saved | 0.5 FTE | 20,000 to 25,000 EUR | On top |
| Recurring cost | Maintenance and hosting | 4,000 to 9,000 EUR | To deduct |
For a public body, the app also feeds the employer mobility plan and fleet decarbonisation reporting with reliable data on real distances driven.
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Mini case study
Jonas, head of facilities at an 800-employee mid-sized company spread across three sites in Berlin and Potsdam, runs 70 leased vehicles at an average 540 EUR per month. He chooses an app at 32,000 EUR with a logbook and a connected key cabinet at the main site (6,500 EUR). After six months, utilisation rises from 36 % to 57 % and he returns 11 vehicles as their leases end, saving 71,280 EUR a year. With 6,000 EUR of yearly maintenance, the initial 38,500 EUR investment pays back in just over seven months.
FAQ
Is an off-the-shelf tool not enough?
SaaS car-sharing tools cost 8 to 20 EUR per vehicle per month, 6,700 to 16,800 EUR a year for 70 vehicles. Custom development makes sense when you have complex priority rules, several sites or deep integration with your IT systems.
Do we need connected keys from day one?
No, many organisations start with a standard key handover and a pick-up confirmation in the app. Connected keys, from 4,000 EUR per cabinet, pay off on sites where more than 15 vehicles move daily.
How do we stop phantom bookings?
The app releases a vehicle automatically if pick-up is not confirmed within 30 minutes, and sends a reminder the day before. That single rule usually cuts no-shows from 20 % to under 5 %.
Is the app GDPR compliant if it tracks vehicle location?
Yes, if tracking is limited to working hours, justified by a specific purpose, documented in the records of processing and agreed with the works council. Trip data is usually kept for 12 months at most, and staff are informed.
How long does a full rollout take?
Allow 3 to 5 months: 3 weeks of scoping, 8 to 12 weeks of development, then a one-month pilot on one site before rollout.
Let's scope your project. We price your booking app from your fleet, your sites and your internal rules, with an indicative budget and a 3 to 5 month schedule. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
