The pair topped a list of mobile spam senders compiled by the Information Commissioner (ICO) with the help of the public.
The ICO got more than 30,000 responses to its plea for help identifying the most incorrigible spammers.
If the spammers cannot prove they had permission to send millions of texts they must pay the fines.
The ICO issued its appeal in March and asked the public to report when they received junk text messages or cold calls on their phone.
The information received helped the ICO identify those companies abusing UK regulations on commercial contact.
