How to cancel the "Deutschland-Ticket" subscription?
According to the legal framework for the "Deutschland-Ticket", cancellation up to the 10th of a month must be done, so that the subscription is terminated at the end of the month. The providers may have deviating deadlines.
DSW21 (Dortmunder Stadtwerke)
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With the provider DWS21 may terminate until the last day of a month.