How Do I Set Up My Custom Portal Domain and DNS Records?

Last updated: October 18, 2026

To put your own domain on your Tonomo portal (for example, portal.yourcompany.com), you'll need to add a few DNS records with your domain's DNS provider. This article covers which records you need, where to add them, and how to avoid the most common setup issues.

What DNS Records Do I Need?

A white-labeled portal needs three kinds of records:

  • A portal CNAME, which points your portal subdomain (e.g. portal.yourcompany.com) to Tonomo's web app.

  • A listings A record, which points your listings subdomain to Tonomo's server IP.

  • SendGrid email authentication records — CNAMEs for an em#### subdomain, s1._domainkey, and s2._domainkey, plus a _dmarc TXT record — so emails send correctly from your domain.

Note: Exact record values are provided by Tonomo support. Reach out, and we can send them to you or your web developer, or add them directly (see below).

The email authentication records are covered in more detail in 📄 How Do I Set Up DNS So Emails Come From My Domain? — Use that article if you're only setting up email sending and not a full white-labeled portal. ​

Where Do I Add These Records?

Add these records wherever your domain's DNS is actually hosted — this is the nameserver provider, which isn't always the same as where you registered the domain.

For example, if your domain's nameservers point to AWS Route 53 or Cloudflare, adding records at your registrar (such as Crazy Domains or GoDaddy) won't have any effect, since the registrar isn't where DNS is actually being resolved. You don't need to change your nameservers to do this — you just need to add the records at the right place.

Not sure where your DNS is hosted? A nameserver lookup tool (like who.is) will show you.

Does This Affect My Main Website?

No. These records only affect your portal subdomain and listings subdomain, plus email authentication — they don't touch your main website at all.

Can Tonomo Add the Records for Me?

Yes. Invite Tonomo support (jpascual@getautonomo.com) to your DNS account, and we can add the records directly.

Setting Up with Cloudflare

Important: If your DNS is hosted on Cloudflare, set the portal CNAME to DNS only (the grey cloud icon, not the orange "proxied" one). A proxied record will show Cloudflare's IPs (104.x / 172.x, and an IPv6 address starting with 2606:4700:) instead of pointing directly to Tonomo, which causes Error 1000: DNS points to prohibited IP.

If your hosting provider (for example, during Firebase domain verification) asks you to "remove" A and AAAA records, go ahead and delete those — you should be left with a single CNAME record.

How Long Does It Take?

After adding or changing records, allow some time for DNS propagation. Newly added or updated DNS records typically take between 5 minutes and 48 hours to fully propagate globally, with most standard changes taking less than 24 hours.

I Changed My Domain or Subdomain — What Do I Update?

If you change your domain or subdomain (for example, switching from book.yourcompany.com to booking.yourcompany.com), reach out to the Tonomo support team. We can redirect your old domain or subdomain to your new one, and keep both active during the transition, so your old links keep working while your clients and agents adjust to the new one.

It's still worth double-checking these in case they reference your old domain directly:

Important: Let the Tonomo support team know before you make any changes to your domain or subdomain, so we can set up the redirect and update the records on our end at the same time. This also lets us coordinate with you to minimize downtime for your portal.

Still Need Help?

If your DNS setup still isn't resolving correctly, send us:

  • Your domain name and the subdomain you're trying to set up (e.g. portal.yourcompany.com)

  • Where your DNS is hosted (your nameserver provider, not necessarily your registrar)

  • A screenshot of your current DNS records

  • Any error message you're seeing (for example, Cloudflare's Error 1000)

  • Whether this is a first-time setup or a domain/subdomain change

A few other things worth checking first: make sure your DNS is actually hosted where you're adding records (not at a different provider, like Squarespace or SiteGround), that your registrar isn't blocking underscore characters in CNAME names, and that your domain hasn't lapsed on renewal.