Commercially made matzah boxes are often stamped with a year that they were produced for, like "Passover 2022". Assuming that the matzah was kept dry and remains sealed, usually in a plastic liner to a cardboard box, is it permissible to use that matzah the next year for the week of Passover and possibly even for the next year's Seder?
The main issue in play here is the issue of מצה ישנה which is parallel to the issue of סוכה ישנה discussed in the first perek of Maseches Sukka.
Relevant sources are:
- תוספתא פסחים ב:יג - which indicates that מצה ישנה is fine for the mitzva as long at is made לשמה
- ירושלמי פסחים ב:ד, סוכה א:ב - which discuss a machlokes Beis Shammai/Beis Hillel re: מצה ישנה
See the following which indicate that מצה ישנה that was initially made לשמה is fine to use for the mitzva of matza forever after (as long as it was kept securely free from chameitz throughout the year):