Should You Always Repay a Loan Early?

When you work through the numbers, the savings thatNOTE
stem from early repayment of a loan can seemThe marginal tax rate is the tax rate you pay on your
almost too good to be true. Can a few dollars a monthlast dollars of income.
really add up to, for example, $25,000 of savings?For example, suppose you have four savings options:
When you save money over long periods of time anda credit card charging 12 percent nondeductible
let the interest compound, the amount of interest youinterest, a mortgage charging 6 percent tax-deductible
ultimately earn becomes very large. In effect, wheninterest, a tax-exempt money market fund earning 4
you pay an extra $20 a month on a 9 percentpercent; and a mutual fund earning 9 percent taxable
mortgage, you're saving $20 each month in a savingsinterest income. To know which of these savings
account that pays 9 percent. By "saving" this $20 overopportunities is best, you need to calculate the
more than 25 years, you earn a lot of interest. In theafter-income-taxes interest rates. If your marginal
earlier example, this monthly $20 really would add upincome tax rate equals 33 percent--meaning you pay
to roughly $23,000.$.33 in income taxes on your last dollars of
But you can't look just at the interest savings. If youincome--the after-income-taxes interest rates are as
placed the same $20 a month into a money marketfollows:
fund, purchased savings bonds, or invested in a stock12 percent interest on the credit card
market mutual fund, you would also accumulate6 percent interest on the mutual fund
interest or investment income.4 percent interest on the mortgage
How can you know whether early repayment of a4 percent interest on the tax-exempt money market
loan makes sense? Simply compare the interest ratefund
on the loan with the interest rate (or investment rate ofIn this case, your best savings opportunity is the credit
return) you would earn on alternative investments. Ifcard; by repaying it you save 12 percent. Next best is
you can place money in a money market fund thatthe mutual fund because even after paying the income
earns 6 percent or repay a mortgage charging you 9taxes, you'll earn 6 percent. Finally, the mortgage and
percent, you'll do better by repaying the mortgage. Itstax-exempt money market fund savings opportunities
interest rate exceeds the interest rate of the moneyproduce 4 percent after you deduct the effect of
market account. But if you can stick money in a smallincome taxes.
company stock fund and earn 12 percent or repay aTIP
mortgage charging you 9 percent, you'll do better byThe difference between percentages such as 12
putting your money in the stock fund.percent and 6 percent may not seem all that large. But
One complicating factor, however, relates to incomechoosing the savings opportunity with the highest
taxes. Some interest expense, such as mortgageafter-income-taxes rate delivers big benefits. If you
interest, is tax-deductible. What's more, some interestinvest $20 each month in something paying 6 percent
income is tax-exempt, and some interest income isn'tafter income taxes, you'll accumulate $5,107 over 25
tax-deferred. Income taxes make early repaymentyears. But if you invest $20 each month in something
decisions a little bit complicated, but here are four rulespaying 12 percent after income taxes, you'll
of thumb:accumulate $13,848 over 25 years.
If you're a business owner with the ability to investThe second complicating factor stems from the tax
additional funds in the business--and that investment willdeduction you sometimes get for certain kinds of
produce extra profits--you should usually make thisinvestments, such as IRAs and 401(k) plans. When you
investment first. Investments in small businesses oftenget an immediate tax deduction, you actually get to
return 20 percent to 30 percent annually. If you canboost your savings amount by the tax deduction. This
get that sort of return, every other opportunity pales ineffectively boosts the interest rate.
comparison. Note that in Chapter 14, I describe how toFor example, if you have an extra $1,000 to save and
estimate the returns you receive from businessuse it to repay a credit card charging 12 percent, you
investments.will save $120 of interest expense (12% * $1,000).
Usually, if you have extra money that you can tie upIf you save the $1,000 in a way that results in a tax
for a long time and can't invest additional moneydeduction, such as through an IRA, things can change
profitably in your business, you'll make the most moneyquite a bit. Say your marginal income tax rate is 33
by saving your money in a way that provides you withpercent. In this case, you can actually contribute $1,500.
an initial tax deduction and where the interest($1,000 / the factor [1-marginal tax rate]). The arithmetic
compounds tax free, such as a 401(k) plan or an IRA.might not make sense, but the result should. If you
(Opportunities in which an employer kicks in an extrahave $1,000 to save but you get a 33 percent tax
amount by matching a portion of your contribution arededuction, you can actually save $1,500, because you'll
usually too good to pass up--if you can afford them.)get a $500 tax deduction ($1,500 #33%).
If you've taken advantage of investment options thatWhat's more, by investing in a tax-deferred
give you tax breaks and you want to save additionalopportunity, you avoid paying income taxes while
money, your next best bet is usually to pay off anyyou're earning interest. (A tax-deferred investment just
loans or credit cards that charge interest you can'tlets you postpone paying the income taxes.) If you
deduct, such as credit card debt. Start with the loan orinvest in a stock mutual fund earning 10 percent, for
credit card charging the highest interest rate and thenexample, you can keep the whole 10 percent as long
work your way down to the loan or credit cardas you leave the money in the stock mutual fund. If
charging the lowest interest rate. For this to reallyyou work out the interest income calculations, you
work, of course, you can't go out and charge a creditwould find that you earn 10 percent on $1,500, or $150.
card back up to its limit after you repay it.So the tax deduction and the tax-deferred interest
If you repay loans with nondeductible interest and youincome mean you'll earn more annually on the stock
still have additional money you want to save, you canmutual fund paying 10 percent than you will save on
begin repaying loans that charge tax-deductiblethe credit card charging 12 percent.
interest. Again, you should start with the loan chargingBe aware that ultimately you pay income taxes on the
the highest interest rate first.money you take out of a tax-deferred investment
Understanding the Mechanicsopportunity, such as an IRA. In the example, you would
Successful saving relies on a simple financial truth: Youneed to pay back the $500 income tax deduction, and
should save money in a way that results in the highestyou would also need to pay income taxes on the $150.
annual interest, including all the income tax effects.(At 33 percent, you would pay $50 of taxes on the
It's tricky to include income taxes in the calculations,$150 of interest income, too.)
however. They affect your savings in two ways. OneIn general, however, if you're saving for retirement, it
way is that they may reduce the interest income youusually still makes sense to go with a savings
receive or the interest expense you save. If interestopportunity that produces a tax deduction and lets you
income is taxed, for example, you need to multiply thepostpone your income taxes. The reason is that the
pretax interest rate by the factor (1-marginal tax rate)income taxes you postpone also boost your
to calculate the after-income-taxes interest rate. And ifsavings--and thereby boost your interest rate. (It's also
interest expense is tax-deductible, you need to multiplypossible that your marginal income tax rate will be
the interest rate by the factor (1-marginal tax rate) tolower when you withdraw money from a tax-deferred
calculate the after-income-taxes interest rate.savings opportunity.