Our journey to zero manual entry: how audit requirements shaped our design

When we started Joulo, manual felt like the honest floor. No connection? Type in your meter reading, attach a photo, done. It worked. And still we have been designing it away, step by step. Not because it was hard for you, but because it does not survive an audit.

What an audit really asks

Every kWh we register for you with the NEa has to be traceable to a measurement. An independent verifier can ask at any moment: show me where this credit comes from. Not "roughly this much", but this meter, this time, this amount of energy.

That requirement has three sides. A registration has to be traceable (every kWh belongs to a measurement, not an estimate), immutable (what is registered does not quietly change) and complete (no gaps, no double counting). We described those three rules in detail in our audit trail. This post is about what they did to our design.

Why manual grates

Put those three rules next to a hand-typed meter reading and the friction is obvious.

A number a person enters by hand is by definition an estimate of what the meter said • not a direct read. The photo helps, but a human still has to read it and copy it over. That is where noise creeps in: a digit wrong, a date off from the reference day, a meter that was just reset.

And the chain is longer than it looks. With an automatic connection the kWh travels from meter to our system without a stop. With manual there is a person in between, and every human step is a place where the chain of proof can break. Not because people are unreliable, but because a verifier does not accept "trust me". A verifier accepts evidence.

Two routes that do produce evidence

So we built two ways that take the human out of the measurement chain.

The first is the automatic connection. You link your charger once • through your brand's API or through OCPP • and from then on every session flows in by itself, straight from the meter. That is the easiest path: set it up and forget it.

The second is the upload. Export your charging sessions from your charge provider's portal or app and drop that file into your dashboard. We now process that export fully automatically • read out, checked and de-duplicated, with no manual review on our end. The difference with manual is fundamental: an export comes straight out of your CPO's metering system. Nobody types anything over.

In both cases we guard the same things. A session that overlaps one already registered is held back. Data we already had through your connection is not counted twice. Traceable, immutable, complete • not as an afterthought checklist, but in how the processing is built.

The MID meter stays the basis

Neither route changes the hard condition: the kWh has to be measured by a MID-certified meter. More and more chargers have one built in. If yours does not, we would rather arrange an upgrade to a charger with a built-in MID meter • and as an alternative you request a secondary allocation point from your grid operator. A separate sub-meter is no longer allowed for home charging under the 2026 Dutch energy-for-transport regulation.

Automatic processing does not make a measurement valid. The measurement has to be right at the source. What our two routes do is get that valid measurement to the NEa provably, without anything getting lost along the way.

Toward zero, not all the way to zero

We are honest about it: we are not at zero manual. But the share is dropping fast. The vast majority of chargers at Joulo now deliver their data automatically, through a connection or an upload. Hand-typed meter readings are a thin edge • for the cases where no other route works yet.

You can see that split live on our status page. It shows the mix of connection types: automatically linked, via upload, and manual. Not a marketing figure, just what is in the system at that moment. We look at that same chart and aim for one thing: making that last sliver of manual as small as possible.

Why this matters to you

You notice nothing of that whole chain of proof, and that is exactly the point. You link your charger or you upload an export, and we make sure every kWh survives an audit. The reason we design manual away is not convenience • it is certainty. The shorter the path from meter to registration, the firmer your credits stand when the verifier knocks.

Registering fast is nice. Registering provably is what counts. We would rather not give up either.

Best, Johan & Ruben