Buy one EV charger and the manufacturer's app is fine. Buy six across two sites, with staff to authorise, energy to report and faults to chase, and you need a back office — software that manages every charge point in one place. The protocol that makes this possible without locking you to a single manufacturer is OCPP, the Open Charge Point Protocol.
What OCPP actually does
It is a common language between chargers and management software. A charger that speaks OCPP can report session records, energy consumed, faults and availability to any compliant back office, and accept instructions back — start and stop a session, authorise an RFID card, set a charging schedule, cap output for load management. Because the language is open, the charger and the software do not have to come from the same company.
That is the whole point. Without it, choosing a charger brand chooses your software, your pricing, and your migration cost for the life of the equipment. With it, you can change back office provider without touching the hardware, and add chargers from a different manufacturer later without splitting your management across two systems.
Versions: 1.6 and 2.0.1
OCPP 1.6 is the workhorse — mature, universally supported, and sufficient for the large majority of commercial sites. OCPP 2.0.1 adds better device management, improved security, richer transaction handling and smart charging features. Most chargers we stock support 1.6; some, including the Sevadis MaxiCharger Gen 2 range, support both. Unless you have a specific requirement, 1.6 is not a limitation today — but if you are buying hardware you expect to keep for a decade, dual support is worth having.
What to check before committing
Is the charger genuinely open, or OCPP-with-conditions? Some manufacturers support OCPP but make connecting to a third-party back office awkward, chargeable, or dependent on unlocking a setting. Ask the direct question before you buy: can this unit connect to a back office of my choosing, and what does that cost?
What is the per-connector cost? Most back offices price per connector per month. On a dual socket charger that is two. Model it across the full site over three years, not per unit — the difference between providers becomes obvious at that scale and not before.
Does it do what you actually need? Most sites need far less than the feature list suggests: session records, RFID authorisation, remote start and stop, fault alerts, and energy reporting. Billing, dynamic pricing, roaming and public network listing matter only if you are running public charging. Do not pay for a public charging platform to run a staff car park.
Can you get your data out? Session history is the record you will need for reimbursement, reporting and any future dispute. Check the export before you commit, not when you are leaving.
When you do not need one
A handful of chargers on one site, free to use, with no billing and no cost allocation, will run perfectly well on the manufacturer's own app. Adding a back office subscription to that is cost without benefit. The tipping point is usually one of three things: more than one site, money changing hands, or someone being accountable for uptime.
Payment is separate
A back office manages the chargers; it does not necessarily take the money. For public pay-per-use you also need a payment terminal — from £335 — or a charger with one built in, such as the Nayax EV Meter Pay at £1,320, which bundles the terminal, the transaction handling and one OCPP connector into a clear £10 monthly fee. And if you are billing per kilowatt hour, the charger needs MID-certified metering, which is a hardware decision made at purchase.
Our position
Every commercial charger we stock supports OCPP 1.6 or later, and we will tell you plainly which ones make third-party connection easy and which do not. If you are scoping a multi-site installation, talk to us before you commit to hardware — the software decision is easier to get right at the start than to unwind afterwards. See also our guides to fleet and depot charging and car park and retail charging.