About the Roja Surname
The spelling Roja grew out of Rojas, a Spanish surname with a long paper trail.
Without the “s” of Rojas, Roja is a simpler written form of the same name. Before spelling was standardised, one family could appear under several forms.
A coat of arms belongs to a particular family line rather than to everyone named Roja, so the heraldry linked to Rojas is a starting point, not an automatic right. Want more than a summary? See the Roja family name pack.