Hello @Michal666 

Are you allready shifted in your new house? If yes then the fastest option would be to get a new subscription for your new house and end the current one. You will be without internet for around 2 weeks unfortunately.

If you are not shifted yet you can report your move to T-Mobile, do it atleast 4 weeks before your shift to your new house.

Read more information here

Hi @Michal666 

Great that your moving house, congratulations! You'll probably have a lot do, so I'll keep this short. You can use your personal My T-Mobile Thuis account to complete the move order. This will be done in no time!
Good luck with the move!