@Agustin Bax 

"I would like to know if I can register those payments as "onwer investment"."

You didn't mention what type of business this is (sole proprietorship, partnership, S-Corp, etc.).  If it's a SP, the appropriate equity account is Owner's Capital.  However, some people use Owner's Equity or Owner's Contributions.  I don't like the term "Owner's Investment" because it denotes they are making an investment when they are, more accurately, increasing their equity.  But, sure, you can use Owner's Investment if you like.