Yes, you can register a new address for children under 18 if you are their legal guardian and they are registered at the same address as you are.
If the other legal guardian is not joining the move, they must consent to the registration in the Swedish Tax Agency's E-service "Lämna samtycke" within a week.
If the other legal guardian does not consent, the Tax Agency will investigate the matter and decide where the child should be registered.
Need help registering a new address for your child?
Please contact us at hej@flyttsmart.se, 08-12 00 88 22 or use the chat function.
You can also read more on the Swedish Tax Agency's website.