Start of user acceptance testing (GAT) on 26 October

Testing activities for topic TS088 ‘Controle naam aangeslotene kleine aansluiting’ (‘Verification name of connected party small connection’) will commence shortly, as part of the January release 2027. From January 2027, suppliers will carry out checks on the reliability and completeness of the connected party’s name details. They will report the results of these checks to the distribution system operators (DSOs).

What is TS088 about?

TS088 stems from Article 2.41 of the Energy Regulations and the Energy Act. Suppliers are obliged to check the accuracy and completeness of the name details of connected parties with small connections within 90 days of the start of supply.

Two streams of information are exchanged with the DSO via the central systems:

• Individual notification ‘Geen zekerheid over juistheid naam’ (‘No certainty regarding name accuracy’): a notification when, following verification, no certainty has been established regarding the accuracy of the name.
• Periodic quarterly report: an aggregated overview of the checks carried out and their results.

Why take part in the GAT tests?

Although participation in the GAT is optional, TS088 is a legally mandatory requirement for suppliers. The GAT period offers your organisation significant benefits:

• Test your own systems against the central systems. In a secure acceptance environment, you can freely test your own IT systems and reporting processes against the central systems.
• Avoid surprises at the go live. The first mandatory quarterly report (covering Q1 2027) must be submitted by 12 May 2027 at the latest. By taking part in the tests, you can be sure that your data exchange will run smoothly before the deadline.
• Benefit from extra support. During the official GAT period, additional support capacity is available to answer questions and resolve any issues. Every Monday morning from 9:00 to 9:30, Het Normo provides support for questions and issues. Testing is possible outside the scheduled test phase, but the support provided will be less intensive (on a best-effort basis).

Register for the GAT tests

If you would like to take part in the tests, please register via the ‘Stel een vraag over een release’ (‘Ask a question about a release’) category on Het Normo’s Marktloket.

Testing and go live schedule for TS088

To ensure that all market parties are ready in good time, testing activities will commence well in advance of the go live date:

• 26 October to 20 November 2026: non-binding GAT tests for all parties involved
• 16 to 25 November 2026: market readiness enquiry for the go live
• 1 January 2027: TS088 goes live
• 31 March 2027: end of the dual phase; market parties must use the API
• 12 May 2027: strict deadline for submission of the first quarterly report (Q1 2027)

TS094 testing in December

In addition to TS088, TS094 ‘Onderscheid AMI AZI in allocatievolumes SMA’ (‘Distinction between AMI and AZI in SMA allocation volumes’) is also part of the January release 2027, affecting balancing responsible parties and DSOs. The GAT tests for this will take place from 7 to 17 December. Further information on this will follow shortly.

What can you do right now?

We do advise you to share the schedule and technical specifications with the IT and process managers within your organisation. You should also consult the Detailed Test Plan on the Energiedatawijzer to prepare your test cases.

Do you have any questions about the preparations, the testing approach or the procedure? Please contact the Marktloket via the ‘Stel een vraag over een release’ (‘Ask a question about a release’) category.

Further information on the Energiedatawijzer

All relevant documentation relating to TS088 can be found on the January release 2027 page on the Energiedatawijzer. Follow the release automatically and receive updates as soon as new publications become available.