I want to type a letter to a company and I don't know the name of the person in charge.
What should I type?
To the responsible? It sounds strange in English.
In Portuguese: 'Para o responsável.'
To whom it may concern
I would use 'Dear Sir or Madam,'(yes, that's a comma) in a letter. I reserve 'To whom it may concern' for testimonials/open references.
What about: 'to the person in charge'