Why can I not (yet) book the requested connection on bahn.de?

There may be various reasons for this. For example:

-         The connection you have selected is too far in the future. We at DB have extended our advance purchase deadline for long-distance services to up to 12 months. This extension does not apply to international and overnight train journeys with other carriers. Here, the advance booking deadline is usually three to six months.

-         Your selected connection is affected by construction work and the timetable is still being adjusted.

-         One of the external booking systems involved is currently unavailable.

Our tip: Try again in a few days. This is often only a temporary problem.