European refineries are not operating in the same environment they were three years ago. More than three months into the Strait of Hormuz disruption, global oil supply has tightened significantly. Inventory buffers across multiple countries are eroding, with some approaching critical levels [S&P Global Ratings, June 2026].
When supply is this tight, every barrel matters more, and so does knowing exactly where it is, what it costs, and how it is accounted for. That is precisely the data most refineries struggle to trust.
The demand for accurate, structured, auditable operational data is arriving from two directions at once: operationally, as disruption makes inventory accuracy more commercially critical; and from a tightening set of EU regulations that increasingly expect the same. European refineries face a more demanding regulatory, economic, and technical environment than almost any other region, and the data systems behind their operations have not always kept pace.
The Problem Most Refineries Are Still Living With
Oil accounting is where operational complexity and commercial accountability meet. Every barrel received, processed, transferred, and dispatched has to be captured accurately, reconciled against physical measurements, and available when required.
Many European refineries have been operating for more than half a century, navigating some of the most demanding compliance frameworks in the world. The challenge is not capability — it is what becomes possible when data that sits across siloed systems is brought into one place. In a tightening margin environment, the cost of fragmented, hard-to-integrate data is no longer just an operational inconvenience. It shows commercially and in the increasing demands of the regulatory frameworks.
Why Now – The Shift Making This Urgent
The regulatory ask has not changed in its existence but in what it now requires. Integration into centralised electronic systems, EMCS, NCTS, and others, has replaced periodic reporting. Data must be available at the point of the movement, not assembled afterward.
The operational environment is making the same demand from a different direction. Supply routes are shifting, schedules are under pressure, and decisions are being made faster with less margin for error. A stock position that cannot be trusted, or a mass balance that takes days to close, is now a commercial risk. Both pressures are live simultaneously.
The Rules Driving the Move
A series of EU updates affect how refineries manage and report operational data. Separate frameworks, different speeds, but broadly aligned in what they demand from the data behind them.
EMCS 4.0 — Excise movements must now be declared electronically before or during movement, not reconstructed afterward. It is live across more than 200,000 registered operators [European Commission, February 2024]. The record has to exist at the point of the movement, not be pulled from emails days later.
Compulsory Stock Obligations – Member states must hold oil stocks equivalent to at least 90 days of average daily net imports or 61 days of average daily inland consumption, whichever is greater [Council Directive 2009/119/EC]. A position assembled from spreadsheets across multiple sites does not meet that. Some refineries lean on solutions like OAS to track inventory across every terminal, depot, and storage location in one place, so the position is always current, not reconstructed for a deadline.
How OAS Supports Refineries on Operational and Regulatory Fronts
The two pressures share one root, and so does the fix.
The data already exists. Every movement, every transfer, every custody change happens and leaves a record, somewhere. The problem is where. Spreadsheets that only one person maintains. Email chains that do not survive a handover. Meter readings logged hours after the fact, if at all. By the time the figures are assembled, the moment to act on them has passed, and when a regulatory deadline arrives, the same chase starts again from scratch.
OAS captures that data at the point it is created, to API and EI standards, in one place. The mass balance is not something you close at month-end. It is the current output of operations you can read today. And because the operational record already exists in structured form, the regulatory reporting draws straight from it, the same data, the same record, already there when the deadline arrives.
Across Europe, OAS users communicate with EMCS to file the required reports. In the UK, HMRC lists OAS as a commercial EMCS software supplier and accepts forms and returns filed through it. For compulsory stock obligations, OAS produces reports that evidence the position. More than 30 refineries across Europe, North America, and Asia-Pacific have already run on it.
OAS users typically achieve full return on investment within twelve months — based on customer-reported outcomes.
The Longer You Wait, The More It Costs
What this article describes is not a forecast. It is the environment European refineries are operating in today. Supply is tighter; regulatory frameworks are stricter, and outdated, fragmented oil accounting systems can no longer keep pace with either. Disconnected systems have a ceiling. Every refinery and terminal will eventually move to a single system of record — today or tomorrow. The only variable is how much it costs to wait. The direction is clear. The only question is when.
If you are struggling to keep up with the current regulatory demands from a fragmented oil accounting environment, speak to the Maron team to see how OAS handles it.