Data quality
ACER's commitment to data quality
ACER, an EU Agency, is entrusted with oversight of trading on Europe’s wholesale energy markets. In 2025, 19.9 bn transactions data was reported to ACER.
Data quality, transparency and confidentiality are cornerstones of our work. We adhere to international standards on how we collect, protect and publish data.
ACER provides evidence of the data quality assessments either by publishing dedicated open letters or via its REMIT quarterlies.
ACER strives to ensure that all collected data is complete, accurate and submitted in a timely way. Our data quality checks follow a two-step approach:
1. Data validation
When data is submitted in a data record by reporting entities to ACER's REMIT Information System (ARIS), automatic validation occurs at two levels:
- technical validation: making sure all data fields in the data record are complete and in the correct format; and
- database validation: ensuring reported data is consistent with reference data.
Any invalid or inconsistent data record is rejected and flagged, ensuring that only information succeeding the preliminary screening is stored in ACER's REMIT database.
2. Quality assessment
After data is collected, ACER's analysts conduct additional quality checks to confirm that it is accurate, complete and reliable, and follow up on any detected issues.
| Dimension | Description | Example |
|---|---|---|
| Completeness | All required data fields for the specific data type are reported. | How much required data has been submitted. |
| Uniqueness | No data record is reported twice. | Duplicate trades are flagged if reported twice. |
| Timeliness | Data is reported correctly after the actual event. | The time difference between when the event occurred and when it was reported is consistent with the timing set in the REMIT Implementing Regulation. |
| Validity | Data follows correct format and rules. | Fields are filled in correctly and match expected structure. |
| Accuracy | Data accurately reflects the business event. | Reported prices, volumes, units, timestamps and identifiers match the real trade. |
| Consistency | Data matches across all reporting platforms. | Same trade reported on different platforms shows the same information. |
