Sigmund Freud helped to popularize excuses and gave them a veneer of respectability by giving them another name. If there is a difference, it is that excuses are usually intended to mislead others, while rationalizations also deceive the one who holds them. Either title implies that the reason is not valid. Excuses are incredibly popular. On the Internet you can find hundreds of sites giving advice on making excuses.
Excuses come in many forms, but are always attempts to barricade oneself from the truth.
And if any one disbelieves that God cares for these things, he will thereby either insinuate that God does not exist, or he will assert that though He exists, He delights in vice, or exists like a stone, and that neither virtue nor vice are anything, but only in the opinion of men these things are reckoned good or evil. And this is the greatest profanity and wickedness. The editor of The Discipleship Journal explained very well why we use rationalizations when she said that we use them to escape the cost of obedience, or to enjoy the pleasure of sin. Like Eve, we know in our hearts that what we want to do is wrong. We can convince ourselves that the blame lies elsewhere, using self-deceit as a means to avoid responsibility.