Q: How long do I need to keep the old domain and its redirects alive after a move — can I let it expire next y

Q: How long do I need to keep the old domain and its redirects alive after a move — can I let it expire next year?

This one trips up people who think a migration has a finish line. It mostly doesn't.

Short answer: keep the redirects for as long as the old URLs earn any external links or clicks — realistically, keep the domain indefinitely.

Long answer: a 301 only passes value while it exists. The day the old domain lapses, every external backlink pointing at it turns into a dead 404, and the authority those links carried evaporates. Google's own guidance is to keep redirects in place for at least a year, but "forever" is the safe answer for any domain that ever earned links. Old domains are cheap insurance; lost link equity is not recoverable.

If the old domain expires, someone can even buy it and you lose all of it permanently.

Next step: set the old domain to auto-renew, keep the 301s live, and re-check backlink reports yearly. Only consider dropping it once no external site still links to it.