Type the phone number in international format and an optional link label. Copy the tel: link or HTML button, and download the QR code PNG for printed material.
Use the international form with a plus sign and digits only, like tel:+442079460958. Brackets, spaces and dashes are technically allowed but some Android dialers mishandle them, so stripping them is the safest choice — this tool does that automatically.
Yes. Add a comma for a short pause followed by the extension digits, for example +442079460958,,123. Each comma is roughly a two-second pause while the call connects, and the dialer then sends the extension as tones.
Yes. The QR encodes the tel: URI, so a phone camera reads it and offers to dial immediately. Because the code is static there is no redirect service involved, so it keeps working even if this site changes.