Assuming responsibility, shouldering the burden, owning up to a mistake, accepting fault, confessing, admitting guilt, acknowledging wrongdoing, facing consequences, bearing the brunt, taking the rap, taking accountability, taking the fall, fessing up, implicating oneself, incriminating oneself, confessing to fault, holding oneself accountable, scapegoating, self-incrimination, falling on one's sword, admitting error, admitting to a blunder, disclosing one's mistake. All of these are synonyms for "taking the blame for", meaning to admit responsibility for something that went wrong or to accept punishment for a mistake committed.