With good storage conditions (dry and at room temperature) our seeds have no specific expiration date. However, over time, the germination rate decreases. You could still try sowing the seeds later than the two or four years we recommend, depending on the variety. It is just likely that fewer plants will sprout.
We only use seeds that are heirloom varieties, other manufacturers often offer F1 hybrid varieties, which usually lose their germination capacity faster. All our seeds are free from pesticides and GMO-free.