In Norway the issuer refunds the overcharge, not the toll company
A Norwegian toll invoice involves two different bodies, and they are easy to mix up. The stations belong to a bompengeselskap — the toll company financing that particular project. But the contract holder is billed by their own AutoPASS issuer (utsteder), and it is the issuer who must compensate lost discounts (utstederforskriften § 16). A claim sent to the toll company goes to a party that cannot settle it.
Why the invoice looks correct
The system holds two kinds of rules. Some the operator must apply itself: one chargeable passage per hour within a passage group (timesregel) and a monthly cap on chargeable passages (passeringstak). Others are defaults applied when data is missing: a vehicle whose emission class is not registered with the issuer is charged the highest rate in its group.
In both cases the invoice line looks equally correct. What differs is what should have happened and did not — and a single line does not show that.
Four places where money disappears quietly
The emission class rate; the hour rule; the monthly cap; the ferry discount tier. Ferries carry their own agreement and their own discount: with an AutoPASS ferry prepayment agreement a business customer gets 40 %, with only a tag 10 %, with neither the full price. On the invoice all three look the same.
What is recoverable and what is only a saving
This distinction is the most important point in the whole audit. If the class is registered and the highest rate was still applied, that is the issuer's error and the amount is recoverable (§ 16). If the class is not registered, supplying the data is the user's obligation (§ 15 c): once registered, the rate applies going forward and says nothing about the past. In the second case the amount is real, but it is not a claim, and we do not call it one.
The same holds for ferries. If the account balance was negative, the discount drops to 10 % under the terms — the reduction is lawful, so there is no basis to demand it back. The loss is real, but it is avoided by topping up in time, not by a claim.
The deadline, and what we do not do
Norway's general limitation period is three years (foreldelsesloven), counted from each payment separately. We do not file the claim with the issuer on your behalf and do not contact them: we state which lines were charged incorrectly and provide a calculation that can be reproduced — the client approaches the issuer.