Add-On Service

Additional to existing contracts, working gas volume, injection capacity or withdrawal capacity can be contracted separately to align your storage portfolio with your specific needs.


The service is an additional service to our primary flexibility services. By contracting additional capacity or volume, the properties of the service can be fine-tuned to meet your specific requirements. Therefore, the Add-On Service has the same specifications as the underlying primary service.


  • Capacity add on to existing contract
  • Volume add on to existing contract
  • Adjustment within boundaries
  • Available at the TTF and Flange

All our firm services are available at the TTF and the Flange. The Accelerator Service is only available at the TTF. Services are offered on bilateral basis and via auctions.
Lead times are based on GTS regulations, with a minimum lead time of 30 minutes. For handling at TTF, an additional lead time of at least  5 minutes is applicable.

Booking reference

Services can be booked upfront with a maximum time-to-service that depends on the duration of the requested service. As an indication, you can take the following guidelines into account.

 Duration of the service  Bookings period, within:
 One until seven days  1 week before the Start Date
 One until four weeks  1 Month before the Start Date
 One until three months  Quarter before the Start Date
 Three until six months  Half year before the Start Date
 More than half year  One year before the Start Date

Our other services