Vercel Domain Verification Not Working? Here's the Real Fix — Plus How to Migrate MongoDB Atlas Between Organizations

By Pradata Tech · May 2026 · 8 min read

We recently took over a live production app from a developer who had set everything up under their own accounts — database, hosting, domain. The client had no ownership of anything. Moving it all over meant solving two problems back to back: Vercel domain verification kept failing even after we added the TXT record, and we needed to migrate the production MongoDB Atlas cluster to the client's own organization without losing data. Here's exactly what we did.

Part 1: Why Vercel Domain Verification Fails (Even After You Add the TXT Record)

The problem

When you add a custom domain to a Vercel project, Vercel asks you to add a TXT record to prove you own the domain. You add it. You wait. Vercel keeps saying "Domain verification failed."

The most common reason this happens — especially on a domain that was previously managed by another developer — is that there is already a _vercel TXT record sitting in your DNS from the old Vercel project. Vercel finds multiple tokens and cannot confirm which account owns the domain, so verification fails silently.

Step 1 — Check what's already in your DNS

Before touching anything, check whether an old _vercel TXT record already exists:

# Mac / Linux
dig TXT _vercel.yourdomain.com

# Windows
nslookup -type=TXT _vercel.yourdomain.com

You can also paste your domain into MXToolbox TXT Lookup or dnschecker.org — no terminal needed. If you see a vc-domain-verify=... value that does not match what Vercel is showing you, that is your problem.

Step 2 — Delete the old TXT record

Log into whichever DNS provider manages the domain — Namecheap, GoDaddy, Cloudflare, Google Domains, etc. Navigate to DNS settings and find the record:

Delete it.

Step 3 — Add Vercel's new TXT record

Copy the exact value from your Vercel dashboard (Settings → Domains). Add a new TXT record:

Step 4 — Wait for propagation, then re-verify

DNS changes are not instant. Depending on the old TTL setting on the deleted record, propagation can take anywhere from a few minutes to a few hours. Use dnschecker.org to watch the new TXT record appear globally before clicking "Verify" in Vercel again — otherwise you are just retrying against a cached version of the old record.

Step 5 — Add the routing records

Once verified, Vercel will ask for the actual routing records so traffic reaches your deployment. Delete any old A records or CNAMEs pointing to the previous host before adding these:

# Apex domain (yourdomain.com)
Type:  A
Name:  @
Value: 76.76.21.21

# www subdomain
Type:  CNAME
Name:  www
Value: cname.vercel-dns.com

Part 2: Migrating a MongoDB Atlas Cluster Between Organizations

The production database was in the previous developer's Atlas organization. The client had no access, no cost visibility, and no control. We needed to move everything to the client's own Atlas account without losing a single document.

Your options

For most apps, mongodump + mongorestore with a short maintenance window is the cleanest path. Here is the full sequence.

Step 1 — Create the new Atlas cluster

In the client's Atlas account, create a new project and spin up a cluster. Match or exceed the compute tier of the old cluster. Then:

• Create a database user with the readWriteAnyDatabase role
• Set the IP Access List to 0.0.0.0/0 temporarily for the migration (lock it down afterward)
• Note the new connection string — you will need it in Step 4

Step 2 — Install MongoDB Database Tools

mongodump and mongorestore are separate from the MongoDB server — you need to install MongoDB Database Tools:

# Mac (Homebrew)
brew tap mongodb/brew
brew install mongodb-database-tools

# Ubuntu / Debian
wget https://fastdl.mongodb.org/tools/db/mongodb-database-tools-ubuntu2004-x86_64-100.9.4.deb
sudo dpkg -i mongodb-database-tools-*.deb

# Windows — download the MSI from mongodb.com/try/download/database-tools

Step 3 — Dump the old cluster

mongodump \
  --uri="mongodb+srv://olduser:oldpassword@oldcluster.mongodb.net" \
  --db=your_database_name \
  --out=./mongo-backup

This creates a ./mongo-backup/your_database_name/ folder with one BSON file per collection. Check that the file sizes look reasonable before moving on — an empty dump usually means a wrong connection string or insufficient permissions.

Step 4 — Restore to the new cluster

mongorestore \
  --uri="mongodb+srv://newuser:newpassword@newcluster.mongodb.net" \
  --dir=./mongo-backup/your_database_name \
  --db=your_database_name \
  --drop

The --drop flag drops each collection in the target before restoring, which is useful if you did a test restore and need to overwrite it cleanly.

Step 5 — Verify document counts

Connect to the new cluster with MongoDB Compass or the shell and spot-check your most important collections:

use your_database_name

// Check total documents per collection
db.getCollectionNames().forEach(name => {
  print(name + ": " + db[name].countDocuments())
})

Compare these numbers against the same query on the old cluster. If they match, you are good.

Step 6 — Update environment variables and deploy

Update the connection string everywhere it lives:

• Your local .env file
• Vercel → Project → Settings → Environment Variables (update for Production, Preview, and Development)
• Any CI/CD pipelines or Docker configs
• Any backend services that connect to the database independently

Redeploy on Vercel, hit a few authenticated routes, confirm data is loading from the new cluster.

Step 7 — Lock down the new cluster

Now that the app is confirmed working:

• Remove the 0.0.0.0/0 IP Access List entry
• Add only the IPs that actually need access (Vercel's outbound IPs if on Pro, or your server IP)
• Rotate the database user password and update the connection string everywhere
• Delete the old backup folder from your machine once you are confident

What We Would Do First on Any Project Takeover

Taking over an app is as much infrastructure archaeology as it is development. A few things we now do on day one before writing any code: