Enter the serial number marked on your Borsini instrument — usually on the valve casing, bell or receiver.
No public Borsini serial table — model codes identify models; dating is feature-based.
The exact spot varies by era and instrument type — the serial number guide walks through the common locations.
Recheck the characters exactly as marked, including any letters and leading zeros. Letter-prefixed numbers often belong to student or non-domestic lines that cannot be dated from the number. Some production periods may simply not be covered yet.