The Deutschlandticket (commonly known as the 49-Euro Ticket) is a subscription-based service, and while it is very flexible, it cannot be canceled at "any time" if you want to avoid paying for the next month. The ticket is technically a monthly rolling subscription. To cancel it and avoid being charged for the following month, you must submit your cancellation by the 10th day of the current month. For example, if you want to stop using the ticket in June, you must cancel it by June 10th; if you wait until June 11th, you will be automatically billed for the month of July. Cancellations are typically done digitally through the app or website where you originally purchased the ticket (such as DB Navigator or a local transport authority app like BVG). It is also important to remember that the ticket is non-transferable and only valid for second-class travel on regional and local transport across Germany (RE, RB, S-Bahn, U-Bahn, buses, and trams); it cannot be used on high-speed ICE, IC, or EC trains. If you miss the 10th-of-the-month deadline, there is generally no way to get a partial refund for the subsequent month.