The verdict in three sentences
After a merger or a rebrand, moving to a new domain is a full SEO project, not a DNS formality. Poorly prepared, the switch loses 10 to 25% of organic traffic for 4 to 12 weeks; well prepared, the dip stays under 10% and traffic returns within 3 months. Indicative 2026 budget: EUR 1,000 to 3,000 (USD 1,200 to 3,500) for the URL audit and mapping, EUR 3,000 to 9,000 (USD 3,500 to 10,000) for full support with page-by-page 301 redirects.
Why traffic drops after a domain change
Google has to recognise that the new domain replaces the old one, transfer authority signals and reindex every page. Anything that muddies that message costs rankings. The causes are almost always the same.
| Common mistake | SEO effect | Estimated traffic loss |
|---|---|---|
| Redirecting every page to the home page | Google treats pages as deleted | 30 to 60% |
| Redirect chains (302 then 301) | Diluted signals, slower crawling | 10 to 20% |
| New site structure at the same time | Double change, slow reindexing | 15 to 30% |
| Forgetting images and PDFs | Lost image and document search traffic | 5 to 10% |
| Old domain not renewed after a year | Broken redirects, lost backlinks | Up to 40% |
| Skipping the Search Console Change of Address tool | Slower transfer | Recovery time doubled |
The golden rule: change one thing at a time. If a redesign is planned, do it before or after the domain move, at least 6 weeks apart.
What a migration costs in Europe and North America
| Step | Indicative 2026 cost (EUR / USD) | Timeline |
|---|---|---|
| SEO audit and URL inventory (crawl, Search Console, backlinks) | 1,000 to 3,000 / 1,200 to 3,500 | 1 to 2 weeks |
| Old URL to new URL mapping | Included or 500 to 1,500 / 600 to 1,700 | 1 week |
| 301 redirect implementation and QA | 800 to 2,500 / 900 to 2,800 | 1 week |
| Internal links, canonicals, hreflang, sitemap updates | 500 to 1,500 / 600 to 1,700 | 1 week |
| Outreach to update key backlinks | 500 to 1,500 / 600 to 1,700 | 2 to 4 weeks |
| Post-migration monitoring over 3 months | 700 to 2,000 / 800 to 2,300 | 12 weeks |
| Full support | 3,000 to 9,000 / 3,500 to 10,000 | 6 to 16 weeks |
A 200-page site with few backlinks sits at the low end. A 5,000-URL site born from merging two companies, with two domains redirecting to a third, sits at the high end.
The migration plan in 8 steps
- Crawl the old site and export every URL that received traffic or links over 16 months.
- Build a page-by-page mapping table, with no mass redirects to the home page.
- Prepare the new domain on staging, blocked from indexing.
- Test redirects on a sample of 100 URLs before the switch.
- Go live on a Tuesday or Wednesday, outside your peak sales period.
- Submit the Change of Address in Google Search Console and the new sitemap, and do the same in Bing Webmaster Tools.
- Ask your 20 to 50 most important referring sites to update their links.
- Keep the old domain and its redirects for at least 3 years, ideally forever.
Merging two companies: a special case
When two sites merge, some pages overlap. Choose the surviving page, merge the useful content and redirect the other one to it. A well-written merged page often captures more traffic than the two originals combined.
For ongoing support after the move, see our SEO services. For a high-constraint project example, read our article on a health insurance member portal in Dublin.
Mini case study
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Emma, marketing director of a B2B manufacturer in Chicago formed through a merger, must move from two domains to a new brand domain. The main site gets 18,000 organic visits a month and generates 90 quote requests, with an average signed deal of USD 13,000 and a 15% close rate.
- Without preparation, an estimated 25% loss over 12 weeks: 90 x 0.25 x 3 = 67 lost requests, about 10 deals and USD 130,000 of revenue.
- With full support at USD 8,000, the loss is limited to 8% over 6 weeks: 90 x 0.08 x 1.5 = 11 requests, fewer than 2 deals.
The gap is about 8 deals, or USD 104,000 of revenue protected for USD 8,000 invested.
FAQ
How long should we keep the old domain?
At least 3 years, ideally forever: renewal costs USD 10 to 50 a year. Old backlinks keep passing value as long as the 301s work.
Is a traffic drop unavoidable?
A 5 to 10% dip for 2 to 4 weeks is normal. More than 20% after 8 weeks almost always points to a redirect error.
Can we change domain and redesign at the same time?
You can, but it is risky: combining both often doubles recovery time, up to 6 months. Separate them by at least 6 weeks if the calendar allows.
Should we tell clients and partners?
Yes, an email to clients and a note to the 20 to 50 main referring sites speed up recovery. Also update email signatures, Google Business Profile listings and industry directories.
How long until traffic is back to normal?
Around 3 months on average for a well-prepared migration, 6 to 9 months if preparation was rushed.
Let's scope your project. Share your current domains, page count and target switch date, and we will scope the audit, the redirect map and the migration calendar. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
