Is the age of my parents' credit card helping my credit more than the balance is hurting it?

Question

I am listed on one of my parents' credit cards with an account age of 37 years. I am 28. This makes my credit history very very old — 37 years old — and significantly older than my oldest credit card. Without this credit card of theirs my credit history is only 10 years old.

However, I have accumulated a large amount of credit history of my own in 10 years, as well as worked down to a 0 balance on all of my credit accounts save a car loan. My current non-carryover balance on my AMEX is ~$2k, which will be paid off between billing cycles and not carry over, and the current balance on my parents' card is ~3.5k and it does carry over.

My combined credit limit on existing credit cards in my name only is ~$73k. The credit limit of my parents' card is ~$13.4k.

Excluding my auto loan and counting only credit cards:

• Current credit utilization with their balance and mine, and the combined total credit limit: 6.206%
• Credit utilization when non-carryover balance is removed, leaving just their balance and their addition to my combined credit limit: 2.343%
• Credit utilization with my non-carryover balance, and their card removed from total used and combined limit: 2.759%
• Credit utilization when non-carryover balance is removed, and their card is removed: 0%

Edited to clarify: The debt on my parents' card is not mine. I was added to this card years ago to buy a spare tire during a road trip and just never got taken off of it. My current credit score is between 780—800 depending on the agency. I'm just gaming for maximum points according to my friends. The only future loan I see myself getting is a mortgage.

Will removing myself from my parents credit card hurt my credit score by making my credit history shorter by over 60%? Or will it improve my credit score by removing a balance and improving my debt available to debt utilized ratio?

Answer 1

If the long term goal is to break the connection, and if the need for a great score isn't urgent just remove your self from the card. The hit will not be forever. Many people have a great score even with credit histories shorter than their age.

I also assume that if the debt that is being rolled over each month is yours that you will discuss this with your parents before you do this.

Answer 2

I don't think removing yourself from your parents' credit card will remove it from you credit report. I am in a similar situation but I was removed as an authorized user of my parents' credit card several years ago, yet it still shows up on my credit report. I also wonder how it affects my credit score. CreditKarma has a Credit Score Simulator that should be able to answer this, but it just says that closing your oldest credit card account will likely decrease your credit score without putting a number on it.