This guide covers changing the nameservers of a main domain in IONOS. Only make this change when Toolbelt Websites has asked you to and has supplied the exact nameserver details.
Before you start
Changing nameservers delegates the domain's DNS management to a different set of nameservers. Have the values supplied by Toolbelt Websites ready and do not guess them.
If you want a plain-English explanation first, read What are nameservers?.
Change the nameservers in IONOS
- Sign in to your IONOS account ↗ and open Domains & SSL.
- Find the required domain. Under Actions, open the menu/gear control and choose Name Server.
- Select Use Custom Name Servers.
- Enter the nameserver details supplied to you by Toolbelt Websites in the fields provided. IONOS currently supports the primary values plus optional additional nameservers.
- Check the values carefully and select Save.
Important: nameservers can affect more than the website
IONOS may be providing DNS, email or other services for the domain. When you switch nameservers, the new nameserver provider becomes responsible for the public DNS zone.
If email records or other service records are not present in that replacement zone, those services can be affected. Do not change nameservers unless instructed, and do not remove email settings at random. See Will changing my website affect my email?.
After the change
IONOS advises that a nameserver change can take up to 48 hours to take effect everywhere. During that period, different networks may temporarily use different DNS information.
See What is DNS propagation? and How long do DNS changes take? for practical guidance.
Official IONOS resource
IONOS also publishes current instructions for this area of its control panel. If the interface has changed since this Toolbelt Websites guide was updated, use the provider's own documentation as the authoritative interface reference.
Last updated: 8 September 2026