RULE: Keep migration 301 redirects in place for at least 12 months; never less than 180 days (Google's explicit floor)
Rule: All 301 redirects implemented during a WordPress migration remain in place for at least 12 months. Never less than 180 days under any circumstances.
Why (Google's own framing): "Maintain the redirects for at least 180 days — longer if you still see any traffic to them from Google Search." (Google Search Central, Change of Address documentation.)
Why (operational, GreenGeeks migration checklist): "Cutting redirects after 30 or 60 days. Google can take much longer to reindex external backlinks. Industry standard is 12 months minimum."
How to apply: the migration build includes redirect retention as a contract clause. Charge for redirect maintenance after the 12-month window as a separate line item if the client wants to extend.
Mistake to avoid: "we'll clean up the redirects" as a tidying task at 30/60/90 days. External backlinks survive longer than internal crawl patterns; cutting redirects too early destroys recovered traffic.
Referenced by (3)
- reference Redirect map deliverable spec — CSV of old→new URL with notes; sources are XML sitemap + Screaming Frog + GSC + Ahrefs/Semrush depends-on
- reference Migration hidden-killers catalogue — the seven failure modes that appear in every post-mortem depends-on
- reference Low-risk cutover pattern for same-domain CMS migration — 2-week pre-flight, DNS TTL 300s, monitor 48h, keep WP firewalled 30 days depends-on