Of all the things that go into a credit score, a discrepancy in mailing address often gets overlooked. It’s important that your address be correct, current, and consistent among all 3 of the major credit bureaus. The Guardian features one woman’s story of what happened due to a lag in public records:

I have no skeletons in my financial cupboard so was surprised to see that in April my Experian rating had dropped from “excellent” to “good” – a massive fall of 80 points. It appeared that Experian had never received details of my address at the time. It explained this was down to the way the local authority updated its electoral roll.

So Experian pulls data from electoral rolls, which are public in this woman’s jurisdiction, and compares it to the address on file for you with other institutions (banks, etc.). The address discrepancy caused this woman’s score to drop 80 points. The usual caveat that “your mileage may vary” applies here, and not all consumers will see exactly the same impact on their scores.

That 80 points can be huge though, particularly if it drops you from one bracket to a lower one, as it did in this woman’s case.

Big kudos to her for monitoring her credit regularly. It sounds like that’s how she caught this error. The moral of this story is to make sure your address is correct, current, and consistent among all 3 bureaus, as well as to check your credit report regularly.