As per Adduxi if you currrently have a VM landline then you will lose your VM phone number when cancelling and your wife signing up as a new customer.
Also should you decide to switch to a new provider instead then you’ll need to check with your new provider if its possible to keep your current VM telephone number, and you need to make sure to do this before your services are current disconnected or you will be unable to port that phone number to the new provider.
In the unlikely event that there are capacity problems in your area then VM may not be taking on any new connections, or they may be unable to supply broadband speeds above M350.
In addition if closing your account then you’ll also lose access to any emails on your Virgin Media account after 90 days once the old account has been disconnected, so you need to back up your emails and/or forward anything important to any new email address that you set up elsewhere. You should also advise your contacts of you new email address.