I get different credit scores from my bank and card companies. What gives?

Dear Liz: I have three financial providers that supply regular, free credit scores: my bank and two credit card issuers. My credit score from the bank is always a “perfect score� while the two card companies are consistently 17 points lower, both exactly the same for two years now. I always pay off most or all of the outstanding balance on time or early. Any clue as to why there is this consistent difference?

Answer: The companies probably are using different credit scoring formulas or different credit bureaus, or both.

You don’t have one credit score. You have many. FICO is the dominant scoring formula, but lenders also use VantageScores and the credit bureaus sometimes provide their own, proprietary scores.

The formulas have been updated over the years. The FICO 8 is the most commonly used score, but the FICO 9 is the latest version and FICO 10 will be introduced this summer. Some scoring formulas are modified to suit different industries, such as auto lending or credit cards, plus each score is calculated from data at one of the three credit bureaus.

So one institution may provide its customers a FICO Score 9 from Experian, another might offer a FICO 8 Bankcard score from Equifax and a third might give you a VantageScore 3.0 from TransUnion. Even if all three were using the same type of score, they probably would use different credit bureaus, or vice versa. To make things even more confusing, your credit scores are constantly changing as your credit bureau information changes.

Furthermore, you typically can’t predict which score or scores a lender will use to evaluate your application for credit. Rather than worry about which number is “right� — they all are — use the free scores as a general indicator of your credit health.

Retirement accounts and taxes

Dear Liz: I am 41 and have had a traditional IRA for about two decades. I funded it for the first 10 years, taking a tax deduction for the contributions. Since I’ve had a 401(k) with my employer for the past several years, I obviously cannot take a deduction for the IRA amount, but I could still put money in. My 401(k) is fully funded, as is my husband’s. Does it make sense to also fund our IRAs with post-tax, nondeductible amounts? I realize any gains we make will be taxed at withdrawal, but I also know that as long as the money stays in the IRA, it can grow tax deferred.

Answer: First, congratulations on taking full advantage of your workplace retirement plans and still being able to contribute more.

You potentially can deduct contributions to IRAs when you have a 401(k) or other workplace retirement plan, but your income must be below certain limits. You can take a full deduction if your modified adjusted gross income is $104,000 or less as a married couple filing jointly. After that, the ability to deduct the contribution starts to phase out and is eliminated entirely if your modified adjusted gross income is $124,000 or more. (If you don’t have a workplace retirement plan but your spouse does, the income limits are higher. The deduction starts to phase out at $196,000 and ends at $206,000.)

If you can’t deduct contributions, you can look into contributing to a Roth IRA — but that too has income limits. For a married couple filing jointly, the ability to contribute to a Roth begins to phase out at modified adjusted gross income of $196,000 and ends at $206,000. If you can contribute, it’s a good deal. Roth IRAs don’t offer an upfront tax break but withdrawals in retirement can be tax free. You also can leave the money alone for as long as you want — there are no required minimum withdrawals starting at age 72, as there typically are for other retirement accounts.

If your income is too high to contribute to a Roth, you could still contribute to your IRA or to any “after tax� options in your 401(k). But you might want to consider simply investing through a regular taxable brokerage account. You don’t get an upfront tax deduction but you could still benefit from favorable capital gains tax rates if you hold investments for a year or more. Furthermore, you aren’t required to take withdrawals. That flexibility can help you better manage your tax bill in retirement.

Liz Weston, Certified Financial Planner, is a personal finance columnist for NerdWallet. Questions may be sent to her at 3940 Laurel Canyon, No. 238, Studio City, CA 91604, or by using the “Contact� form at asklizweston.com.