When can the QR-bill be used?

The QR-bill is replacing the currently used payment slips. Can, however, physical payment instructions be still submitted at banks or can payments still be made at post office counters?

The current forms of the payment slip will be replaced by the QR-bill and thus disappear. Will it only be possible to invoice with QR-bills in the future?

What is going to happen with the currently used blank payment slips?

As of when can the current payment slips no longer be used?

How is it being assured that companies will be involved on time and will be ready?