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Blogger Custom Domain Error 12: How to Fix It
Blogger's Error 12, which says it has not been able to verify your authority to the domain, means Blogger cannot see the two CNAME records it needs at your DNS provider. The fix is to add both records exactly as Blogger shows them, make sure nothing else is using the same host name, wait at least an hour as Google advises, and then press Save again. If it still fails, the usual causes are a conflicting record, a Cloudflare proxy or a typo in the Name field.
Key Takeaway: Error 12 is not a Blogger bug or a block on your account. It is a DNS check that fails until Blogger finds two specific CNAME records. Most fixes take one corrected record and some waiting.
What Error 12 actually means
When you add a custom domain in Blogger, it checks your DNS. If it cannot find what it expects, it shows a red message along the lines of "We have not been able to verify your authority to this domain. Error 12," together with two records you need to create. Google's Blogger Help describes this as the step where you "get an error with 2 CNAMEs," which is a normal part of the setup, not a sign that something is broken.
The two records are:
| Record | Name (Host / Label) | Destination (Target / Points to) |
|---|---|---|
| Blog CNAME | The subdomain you entered, like www or blog | ghs.google.com |
| Security CNAME | A unique name shown by Blogger, different for each blog and Google account | A unique value shown by Blogger |
Google also notes that in some setups you may not have to enter the two CNAMEs at all. If Blogger does not ask for them, you do not need to add them.
Fix Error 12 step by step
- Get the records from Blogger. Open Settings, find the Publishing section and click Custom domain. Enter your domain, usually with www in front, and click Save. Keep the error screen open or copy both CNAMEs exactly. The names shown stay the same each time you try, so you do not need to refresh to "get new ones." A blogger who tested this reported the same names every time he pressed Save.
- Open your DNS settings. Log in where you bought or manage the domain, whether that is GoDaddy, Namecheap, Squarespace or another provider, and find the DNS settings. Menu names differ by provider, so look for fields called Name, Host or Label, and Destination, Target or Points to.
- Add the Blog CNAME. Name: the subdomain, like www. Destination: ghs.google.com.
- Add the Security CNAME. Copy the unique name and destination from the Blogger error screen. Copy and paste instead of typing, because one wrong character is enough to fail.
- Check how the record was saved. Some DNS panels add your domain name for you. If you typed the full name there, you can end up with the domain written twice. Look at the finished list and compare it with what Blogger asked for.
- Remove conflicts. A host name such as www should have only one record. If an old A record, a parking page or a "URL forwarding" record already uses www, remove or replace it before adding the CNAME. This is a general DNS rule, and it is the most common reason a provider refuses to add the record.
- Wait at least one hour. Google's help page says to wait at least an hour for DNS settings to activate before you repeat the setup in Blogger.
- Press Save again in Blogger. Go back to Settings, Publishing, Custom domain and save the domain again.
If it still says Error 12
| What you see | Likely cause | What to check |
|---|---|---|
| Provider will not let you add the CNAME | Another record already uses that name | Remove the old A record, parking page or forwarding record for www |
| Records look right but Blogger still fails | Cloudflare proxy is on | Set both CNAME records to DNS only (grey cloud) |
| Lookup tool shows nothing | Wrong Name field or DNS not updated yet | Compare the saved name with Blogger's, then wait longer |
| Worked once, then stopped | Records were changed or deleted | Check that both CNAMEs are still in your DNS list |
The Cloudflare check
If your DNS runs through Cloudflare, a proxied record (orange cloud) answers lookups with Cloudflare's own addresses instead of showing the CNAME. Cloudflare's own community guidance says this can cause trouble when a service uses the CNAME record to confirm you own the domain, and the fix is to turn the proxy off for that record (grey cloud, "DNS only"). Do that for both Blogger CNAME records, and for any A records you add for the root domain.
Root domain, HTTPS and the blogspot redirect
Error 12 is about verification, but the same setup also covers three other things that make a domain look "not working."
- Opening example.com without www. Blogger Help says to add four A records that point to Google's IP addresses: 216.239.32.21, 216.239.34.21, 216.239.36.21 and 216.239.38.21. If other A records already exist for the root domain, remove them. Then turn on Redirect domain under Publishing so the root domain goes to the www version.
- HTTPS not working. If your domain uses CAA records, you must add one for letsencrypt.org. Google says that without it, Blogger will not create or renew your SSL certificate.
- The blogspot address still shows. Google says your blogspot.com address can take up to 24 hours to redirect to your custom domain.
After the domain works
Once the domain loads, two jobs are left. First, if you earn from AdSense, check that your new domain is in your AdSense sites list and that ads.txt is in place. My guide to the Blogger ads.txt "Earnings at Risk" fix explains what to look for. Second, add the new domain to Google Search Console and watch for new errors. My guide to why Search Console shows errors covers the usual ones.
What this guide cannot promise
- Exact waiting time. Google says to wait at least an hour, and the blogspot redirect can take up to 24 hours. Provider speed varies, so there is no fixed number.
- Provider menus. Every DNS provider labels things differently, so I describe fields instead of exact clicks. If you are stuck on a provider step, Google's help page says to contact your domain provider.
- Your individual case. If the records are correct and a lookup tool shows them, but Blogger still fails, post the exact error in the Blogger Help Community.
Final thoughts
Error 12 looks scary, but it is almost always one record: a wrong name, a conflicting record, or a proxy that hides the CNAME. Add both records, remove anything in the way, wait an hour and try again. Most setups work the second time.
Pro Tip: After your domain is live, save a screenshot of your full DNS list in a safe place. If you ever change providers or lose access, you will know exactly which records Blogger needs.
Sources and limits: this article is based on Google's Blogger Help page "Set up a custom domain," reviewed on October 15, 2026, plus a Cloudflare community answer about proxied DNS records and a blogger's report of his own setup. Google's page does not quote the Error 12 wording or list provider-specific steps, so the table of causes beyond Google's own advice is my own reading, and the general DNS points (conflicting records, saved names) are not from Google. This is general information, not a guarantee that your setup will work.
