How to Remove an Alias Domain in ISPConfig

This guide covers removing an alias domain from a website in the ISPConfig control panel on your Noiz hosting account, and, more importantly, what actually happens afterwards. Adding an alias domain (ISPConfig calls it an "aliasdomain"; you may also see it called a parked domain or a domain alias) is covered in How to Add an Alias Domain in ISPConfig. Taking one away is a two-click job, so the deletion itself is not the interesting part. What is worth reading is how to be certain you are deleting an alias and not a whole website, whether you want to delete it at all or simply switch it off, and the knock-on effects on DNS and on your main site's SSL certificate that are easy to trip over.

Last reviewed: 27 July 2026, against the current ISPConfig release. This guide is written for Noiz hosting and is kept current against ISPConfig. It complements, and does not replace, the official ISPConfig documentation linked below.

Official Documentation Reference

• ISPConfig Documentation: Alias Web Domains: the official walk-through for creating an alias domain. It documents creation only, which is why removal is covered here.
• ISPConfig 3 User Manual: the official manual. Section 4.6.1.4 Aliasdomain for website is the field-by-field reference for the Web Aliasdomain form, useful if you decide to edit rather than delete, and 4.6.1.5 Aliasdomain (Vhost) covers the variant discussed below.
• ISPConfig Documentation overview: the index of official ISPConfig documentation.

Prerequisites

• You can log in to the ISPConfig control panel.
• You know which domain you want to stop serving, and which website it is currently attached to.
• You know where the domain's DNS is managed, because the panel change and the DNS change are two separate jobs. If the zone is on Noiz nameservers, see How to Manage DNS Records in ISPConfig.

First, Confirm It Really Is an Alias Domain

This is the one step that genuinely matters, because the panel puts several different objects in lists that look almost identical, and only one of them is safe to delete casually.

An alias domain is a name; a website is a container

• An alias domain is nothing more than an extra name bolted onto an existing website. It has no files of its own, no document root of its own, no database, no PHP settings, no logs and no disk quota. Everything it shows belongs to the parent website. Deleting it removes the name and nothing else. If you get it wrong, you simply add it back.
• A website is the container itself: its own virtual host, its own document root and files, its own PHP configuration, its own certificate, its own statistics and logs. Deleting a website in ISPConfig removes the site's directory and its contents. There is no undo button in the panel for that, and recovery means a restore from backup.
• A subdomain (such as shop.yourdomain.com) sits under the parent website's own domain name, whereas an alias domain is a different domain name entirely. If the name you want gone is a subdomain, see How to Create a Subdomain in ISPConfig for where those live in the panel.

How to tell which one you are looking at

1. Log in to ISPConfig and open the Sites module.
2. In the left-hand menu under Websites, open Aliasdomain for website. The page is headed Aliasdomains, and each row shows the alias domain name with the site it is attached to in the Website column. If the domain appears in this list, it is a true alias domain and safe to delete.
3. If it does not appear there, check the Websites list. A domain sitting in that list is a full website. Deleting it deletes its files, so treat it as a completely different task and take a backup first.
4. If your server has the feature enabled, you may also see Aliasdomain (Vhost) in the left menu. That is a hybrid: an alias name that does have a document root of its own, inside the parent website's directory. Deleting one of those can take a folder of files with it, so download anything you want to keep before you remove it.

A useful sanity check: if the domain has ever had its own files uploaded to it, its own WordPress install or its own database, it is not a plain alias domain, whatever it is called in conversation.

Decide: Switch It Off, or Delete It

The panel gives you two ways to stop an alias domain serving your site, and the official documentation does not draw the distinction. It matters more than it looks.

• Deactivate (recommended when you are not certain). Open the alias domain, clear the Active tick box and save. The name stops answering, but the record, its redirect settings and its link to the parent website all survive. Re-ticking the box puts everything back exactly as it was. This is the right choice for a temporary change, a trial, or any situation where somebody might ask for the domain back next week. The trade-off is that the entry still counts against your hosting package's alias domain allowance, because the client limit ISPConfig calls Max. number of web aliasdomains counts the records rather than the active ones. The name also stays reserved inside the panel, so you cannot use it elsewhere.
• Delete. The record is removed for good. This frees the alias domain allowance for another domain, and it releases the name so it can be used again in the panel, which is exactly what you need if the plan is to promote the domain to a website of its own. Any redirect type, redirect path, auto-subdomain and SEO redirect settings you configured on it are gone, and recreating the alias means re-entering them.

One decision worth pausing on: if the alias domain is currently a permanent (R=301,L) redirect to your main address, it is doing real work for search engines by consolidating an old domain onto the new one. Deleting it throws that away, and any ranking or backlink value attached to the old domain stops being passed on. If the only reason for removal is tidiness, leaving a 301 alias in place costs you nothing. See Google Search Central: redirects and Google Search for why that matters, and How to Set Up a Website Redirect in ISPConfig if you would rather change the redirect than remove the domain.

Remove the Alias Domain

1. In Sites > Aliasdomain for website, find the row for the domain and check the Website column one last time. The same setting is labelled Parent Website when you open the record itself. Two similar-looking domains in the same list is exactly how the wrong one gets deleted.
2. Click the delete control at the right-hand end of the row (a small bin or cross icon, depending on the panel theme).
3. Confirm when the panel asks whether you really want to delete the record.
4. The row disappears from the list. ISPConfig then queues the change, rewrites the parent website's virtual host without that name and reloads the web server. That queue is processed on a schedule rather than instantly, so allow a minute or two: the panel showing the record as gone and the live server actually behaving differently are not the same moment.

What Changes the Moment It Is Gone

Visitors using that domain stop reaching the site

That is the whole point, but it is worth being precise about what a visitor actually sees, because it is rarely a tidy error page from your own site.

• If the domain's DNS still points at the Noiz server (the usual case immediately after removal), the request still arrives, but no website on that server claims the name any more. The web server hands it to whatever it treats as the default, so visitors typically land on a generic placeholder or "site not configured" page rather than anything of yours. Over https:// they will usually hit a certificate name-mismatch warning before they get that far.
• If you have also removed the DNS records, the browser fails at the lookup instead and reports that the server cannot be found.
• Everything that hard-codes the domain breaks with it: bookmarks, links from other sites, search engine results still listing the alias, email signatures, printed material, QR codes, and any third-party integration, webhook or callback URL configured to use that hostname. Search results in particular can take weeks to drop away, so people will keep arriving at a broken address for a while.

Removing an alias domain never touches the parent website's own domain, its files or its content. If your main site goes down at the same moment, something else has happened; see Troubleshooting below.

DNS is not touched at all

ISPConfig's alias domain record configures the web server, and nothing else. Deleting it leaves the domain's A records, CNAMEs and everything else in the zone exactly as they were, still pointing at the server. Tidying the DNS is a separate job, done either in the panel if the zone is hosted with Noiz or at whichever provider holds the zone. If the domain is moving to a new host, changing the A record is what actually moves it; removing the alias in ISPConfig only stops the old server answering for it.

SSL: the order you do things in matters

This is the trap that catches people, because the risk lands on the certificate for your main site rather than on the alias.

ISPConfig builds the parent website's free SSL certificate request from all the names currently attached to that site: the site's own domain, its auto-subdomain, and every alias domain and subdomain that is marked active, plus the www form of any of those whose auto-subdomain is set. Deactivating an alias domain takes it off that list just as surely as deleting it does. Every one of those names has to answer a validation request from the internet each time the certificate is issued or renewed, which is why the official documentation insists that all of them resolve to the server before you switch free SSL on.

Before the request goes out, ISPConfig tests each name over HTTP and quietly leaves out any that does not answer on this server, so a name whose DNS has already gone is usually dropped rather than sinking the request. What does sink it is a name that answers but then fails the certificate authority's own validation, a redirect sitting in front of it being the common cause: the request fails for the whole site, and the site keeps serving its existing certificate until a later attempt succeeds. Do it in this order and neither case can bite you:

1. Remove (or deactivate) the alias domain in ISPConfig.
2. Let the parent website's certificate be reissued without that name. Removing an alias domain makes ISPConfig rebuild the parent site and ask for a fresh certificate as part of the same job. If it does not refresh on its own, re-saving the website in Sites > Websites triggers another request. See How to Secure a Website with a Free SSL Certificate in ISPConfig.
3. Only then change or remove the domain's DNS records.

If the alias has to stay attached but can no longer answer for itself, there is a third option: the alias domain form carries a Don't add to Let's Encrypt certificate tick box, which keeps the name off the request without deleting or deactivating the record.

Two smaller points. The certificate already installed on the server keeps listing the removed name until it is next reissued, which is harmless: a name being listed on a certificate does not make the server serve a site for it. And no certificate is revoked by this; the old name simply stops appearing on the next one issued. Background on how those certificates are issued and renewed is in the Let's Encrypt FAQ.

Email for that domain is a separate matter

A web alias domain and a mail domain are unrelated objects in ISPConfig. Deleting the alias under Sites does not remove anything under Email: mailboxes, aliases, forwards and the mail domain itself all keep working, and mail carries on being delivered. If you want mail for the domain gone too, that is a deliberate separate deletion in the Email module, and removing an email domain takes its mailboxes and their stored messages with it. Download anything you need first.

Confirm It Worked

1. The row no longer appears in Sites > Aliasdomain for website. If you deactivated instead, the row is still there but no longer marked active.
2. Open the removed domain in a private or incognito window, or on a phone using mobile data. Your normal browser is the least reliable place to test this, especially if the alias was a permanent redirect: browsers cache a 301 aggressively and will keep sending you to the old destination long after the server has stopped issuing it.
3. Check what the server now says for that name from a command line:

   curl -sI http://yourseconddomain.com

   Replace yourseconddomain.com with the domain you removed. You should no longer see a response that belongs to your site.
4. Most important, confirm the parent website is still healthy, both the page itself and the padlock:

   curl -sI https://www.yourdomain.com

   Replace yourdomain.com with your real domain. Load it in a browser too and check the certificate has not developed a warning.

Troubleshooting

Symptom: the removed domain still shows your website. Almost always caching rather than a failed deletion. Retest in a private window or from a different network. If the domain sits behind a proxy or CDN, that service is serving its own cached copy and needs its cache purged. If it genuinely still serves your content from a clean client, check whether the same name also exists as a website, a subdomain or a Vhost alias domain elsewhere in the Sites module.

Symptom: the domain now shows a page belonging to somebody else, or an unfamiliar placeholder. This is expected, not a fault. The DNS still points at the server while no site claims the name, so the request falls through to the server default. Repoint or remove the domain's DNS records to stop it.

Symptom: the deletion is refused with "You dont have the permission to delete this record!". Every row in the list carries a delete control, so this is a permissions block rather than a missing button: a record that an administrator created on your behalf can be handed to your account with read and edit rights but not delete, which is most often seen on a website or a Vhost alias domain. A domain belonging to a different client does not appear in your list at all. Open a support ticket rather than trying to work around it.

Symptom: your main website shows a certificate warning after the removal. The site's certificate request is failing on one of the names still attached to it. Re-save the website in Sites > Websites to trigger a fresh request, and check that every remaining alias domain and subdomain on that site still resolves to the server. If it does not clear, raise a ticket.

Symptom: ISPConfig reports "There is already a website or sub / aliasdomain with this domain name" when you try to recreate the domain as a website of its own. The old alias record is still in the panel. A name can only be held by one object at a time, so delete the alias first, then create the website. The full procedure is in How to Create a Website in ISPConfig. Note that promoting a domain this way gives it an empty document root, so the content has to be put there separately.

Symptom: you deleted the wrong entry. If it was an alias domain, no harm is done: recreate it using How to Add an Alias Domain in ISPConfig and re-enter the redirect and auto-subdomain settings. If it was a website or a Vhost alias domain, stop making further changes and contact Noiz support immediately, because the sooner a restore is attempted the better the outcome.

If you are unsure whether the domain in front of you is an alias or a full website, ask before you click delete rather than after. Open a support ticket with the Noiz support team, quoting the domain name and the website you believe it belongs to, and on managed plans the team will confirm what the record actually is, remove it for you, and check that the parent site's certificate reissues cleanly afterwards.