There are several common misconceptions about what happens to an individual's credit reports after marriage. One of the most common myths is that when you are married your credit reports will merge together with your spouse's reports, which may even hurt or improve your credit scores depending upon the strength of your partner's credit history. The fact is credit reports and credit scores are tied directly to individual social security numbers. You might choose to take on a new last name after marriage, but your social security number will stay the same, and so will your credit reports.
If you do change your last name after marriage, be sure to report the change to all your creditors in a timely manner. Mistakes can easily happen during this time period, so don't forget to carefully monitor your credit reports for several months and dispute any inaccuracies before they escalate into larger issues.