The situation
A migration that went live without redirect mapping — and lost £40K/month overnight
The client — a UK home furnishings retailer with a well-established organic presence built over seven years — migrated from Shopify to a custom-built platform in May 2024. The new platform launched on a Monday morning. By Wednesday, the owner noticed something was wrong. By Friday, Google Search Console confirmed the catastrophe: 1,200+ product and category URLs had changed without redirects, 70% of organic traffic had vanished, and organic revenue — which had been averaging £58K/month — had dropped to under £18K in the first week.
They contacted their previous SEO agency, who told them recovery would take 12–18 months. Unconvinced, they came to us for a second opinion. We told them 90 days was achievable with immediate, intensive action — and we started work the same afternoon.
Core challenges
Four distinct problems compounding each other
1,200+ broken URLs with no redirects
Every product, category, and blog URL had changed in the migration. Without 301 redirects, Google was serving 404 errors to users clicking search results — destroying click-through rates and signalling to Google that the content no longer existed.
Crawl budget wasted on 404s
Googlebot was spending its entire crawl budget discovering and re-discovering 404 pages. New content on the site was not being crawled or indexed because the bot was trapped in an error loop.
Robots.txt misconfiguration
The new platform had launched with a restrictive robots.txt that was accidentally blocking Googlebot from crawling the product category pages — the highest-value pages in the site's organic portfolio.
Lost internal link equity
Seven years of internal links — in blog posts, related product sections, and navigation — now pointed to 404 pages. The internal PageRank distribution had effectively been reset to zero.
Our approach
A structured 6-phase SEO programme
We built a phased plan that addressed technical foundations first, then content, then authority — in that order. Skipping the technical audit would have wasted the content investment.
1
48-hour emergency triage
Day 1: crawled the old Shopify sitemap from Google's cache and the new site simultaneously. Produced a complete old-to-new URL mapping for all 1,200+ pages. Day 2: submitted the redirect map to the development team with implementation instructions. Redirects live within 36 hours of project start.
Sitemap from Google cache1,200+ URL mappingRedirect brief to devsImplemented in 36 hours
2
Robots.txt and sitemap fix
Identified and corrected the robots.txt rule blocking category pages. Rebuilt the XML sitemap to include only indexable pages. Submitted to Google Search Console with a recrawl request. Category pages began appearing in search results within 12 days.
Robots.txt correctedXML sitemap rebuiltSearch Console submissionRecrawl request
3
Coverage report and index recovery
Monitored Google Search Console coverage report daily. Identified 340 pages that were redirected but not yet re-indexed. Used URL Inspection tool to request indexing for priority commercial pages. Tracked indexing rate against pre-migration baseline.
Daily GSC monitoringURL Inspection toolPriority page indexingIndexation tracking
4
Internal link audit and repair
Crawled the new site to find all internal links pointing to now-redirected URLs. Updated 2,800+ internal links to point directly to new canonical URLs (redirects work, but direct links pass more equity). Blog posts updated first, then navigation templates.
2,800+ internal links updatedBlog posts prioritisedNavigation templatesCanonical URL linking
5
Content and schema verification
Verified that all structured data from the old site had been carried across correctly. 180 product pages had lost their schema markup in the migration. Rebuilt and re-deployed schema for all affected pages.
Schema audit180 pages rebuiltProduct schemaStructured data validation
6
Ongoing monitoring and prevention
Set up automated weekly crawls with Screaming Frog via scheduler. Configured Google Search Console alerts for coverage errors. Produced a migration checklist document the client's development team must follow for any future platform changes.
Automated weekly crawlsGSC error alertsMigration checklistDev team documentation
Month by month
How progress unfolded
Days 1–2 — June
Emergency triage
Old Shopify sitemap retrieved from Google's cache. 1,200+ URL mapping produced. Redirect brief delivered to developers. Robots.txt error identified and flagged.
Days 3–7
Redirects and fixes live
All 1,200+ redirects implemented by the dev team. Robots.txt corrected. New sitemap submitted. Immediate improvement in Search Console coverage errors.
Days 8–30 — July
Index recovery begins
Category pages returning to search results. Organic traffic recovering at approximately 8–12% per week. Internal link audit and repair completed for 2,800+ links.
Days 31–60 — August
Momentum builds
Top 50 commercial keywords back in top 20. Traffic at 68% of pre-migration level. Revenue recovering. Schema rebuilt for all 180 affected product pages.
Days 61–90 — September
Full recovery and beyond
Organic traffic exceeded pre-migration levels by week 12. Revenue hit £92K in September — 160% of the pre-migration average of £58K. Rankings for 14 priority keywords now higher than pre-migration positions.
Results: before vs. after
The numbers speak clearly
Before migration (April 2024)
Monthly organic trafficBaseline (100%)
Monthly organic revenue£58,000
Pages returning 404 errors0
Pages returning 404 errors (now)1,200+
Robots.txt blockingNone
Internal links to live URLs100%
Schema markup coverage100%
After recovery (September 2024)
Monthly organic trafficRestored + 18% above baseline
Monthly organic revenue£92,000
Pages returning 404 errors1,200+ (post-migration)
Pages returning 404 errors (now)4 (minor orphan pages)
Robots.txt blockingCorrected (was blocking categories)
Internal links to live URLsBack to 100% (2,800+ repaired)
Schema markup coverage100% (180 pages rebuilt)
100%
Organic traffic fully restored within 90 days
+160%
Revenue vs pre-migration average (£92K vs £58K)
1,200+
URLs rescued with redirect mapping
"
On day three after launch, I was looking at Search Console and felt physically sick. Seven years of SEO work, gone. Our other agency said 12 to 18 months. These people started work the same afternoon I called them, had redirects live the next day, and we were back to normal traffic within 90 days. The fact that revenue actually ended up higher than before the migration still seems impossible to me.