A method for correcting a tilted position of a moving product to be folded on a folding table of a longitudinal folding apparatus comprising a folding blade at least prior to the folding along a transport direction on the folding table, wherein, - the folding blade is driven by a drive motor mechanically independent of a conveyor belt arranged upstream conveying products, - at two measurement points (S3; S4) lying in the region of the folding table between an input area and a stop device restricting the transport path in transport direction in the active state, in each case a moment of passage of a leading or trailing edge of the product is detected, wherein the two measurement points (S3; S4) are spaced apart from one other by at least 100 mm and arranged transversely to the direction of transport of the product to be folded and are arranged at essentially the same distance of at least 20 mm to the position of a stop surface of the stop device restricting the transport path in transport direction in the active state, - based on the moments of passage detected at the two measurement points (S3; S4) and on commutation and/or data processing techniques, a deviation Δt1 between a time offset detected during the passage of the corresponding product edge at the two measurement points (S3; S4) and a nominal time offset is determined and analyzed, - in the event that the deviation Δt1 exceeds at least the tolerance range, a measure is initiated according to a control process in order to act against the deviation Δt1 and for the purpose of influencing an asymmetrical delay or acceleration of the products which are displaced on the folding table - and the stop device is disengaged in an operating situation during the folding operation. - the folding blade is driven by a drive motor mechanically independent of a conveyor belt arranged upstream conveying products, - at two measurement points (S3; S4) lying in the region of the folding table between an input area and a stop device restricting the transport path in transport direction in the active state, in each case a moment of passage of a leading or trailing edge of the product is detected, wherein the two measurement points (S3; S4) are spaced apart from one other by at least 100 mm and arranged transversely to the direction of transport of the product to be folded and are arranged at essentially the same distance of at least 20 mm to the position of a stop surface of the stop device restricting the transport path in transport direction in the active state, - based on the moments of passage detected at the two measurement points (S3; S4) and on commutation and/or data processing techniques, a deviation Δt1 between a time offset detected during the passage of the corresponding product edge at the two measurement points (S3; S4) and a nominal time offset is determined and analyzed, - in the event that the deviation Δt1 exceeds at least the tolerance range, a measure is initiated according to a control process in order to act against the deviation Δt1 and for the purpose of influencing an asymmetrical delay or acceleration of the products which are displaced on the folding table - and the stop device is disengaged in an operating situation during the folding operation.