Portuguese to English Law/Patents Law: Contract(s) Terms of use

Dear fellow translators,

The term I am in search for is "fundamento". Here is the full paragraph where it is used:

A responsabilidade total da empresa e de suas controladoras, controladas ou coligadas no tocante a todas as ações e reclamações relacionadas a este Termo de Uso ou a qualquer serviço fornecido sob este instrumento, independentemente do fundamento de referidas ações e reclamações, não excederá o valor do preço dos serviços contratados.

As you can see, it is a paragraph describing rules of procedures that appear in a Term and Conditions document.

Here is my translation:

The full liability of the company and its affiliates, controlled and parent companies concerning all actions and complaints related to this Term of Use, or to any other service provided in this document, regardless the nature of the referred actions and complaints, it will not exceed the price of the services acquired.

I used "nature" as a solution, but I think it does not carry the full meaning of the word "fundamento", and I didn't like the synonyms I found, such as root, basis, or foundation itself.

Any help will be appreciated!

Thank you.