Why Tax Basis Is So Important

Why Tax Basis Is So Important

For tax purposes, the term “basis” refers to the original monetary value that is used to measure a gain or loss. For instance, if you purchase shares of a stock for $1,000, your basis in that stock is $1,000; if you then sell those shares for $3,000, the gain is calculated based on the difference between the sales price and the basis: $3,000 – $1,000 = $2,000. This is a simplified example, of course—under actual circumstances, purchase and sale costs are added to the basis of the stock—but it gives an introduction to the concept of tax basis.

The basis of an asset is very important because it is used to calculate deductions for depreciation, casualties, and depletion, as well as gains or losses on the disposition of that asset.

The basis is not always equal to the original purchase cost. It is determined in a different way for purchases, gifts, and inheritances. In addition, the basis is not a fixed value, as it can increase as a result of improvements or decrease as a result of business depreciation or casualty losses. This article explores how the basis is determined in various circumstances.

Cost Basis – The cost basis (or unadjusted basis) is the amount originally paid for an item before any improvements and before any business depreciation, expensing, or adjustments as a result of a casualty loss.

Adjusted Basis – The adjusted basis starts with the original cost basis (or gift or inherited basis), then incorporates the following adjustments:

  • increases for any improvements (not including repairs),
  • reductions for any claimed business depreciation or expensing deductions, and
  • reductions for any claimed personal or business casualty-loss deductions.

Example: You purchased a home for $250,000, which is the cost basis. You added a room for $50,000 and a solar electric system for $25,000, then replaced the old windows with energy-efficient double-paned windows at a cost of $36,000. The adjusted basis is thus $250,000 + $50,000 + $25,000 + $36,000 = $361,000. Your payments for repairs and repainting, however, are maintenance expenses; they are not tax deductible and do not add to the basis.

Example: As the owner of a welding company, you purchased a portable trailer-mounted welder and generator for $6,000. After owning it for 3 years, you then decide to sell it and buy a larger one. During this period, you used it in your business and deducted $3,376 in related deprecation on your tax returns. Thus, the adjusted basis of the welder is $6,000 – $3,376 = $2,624.

Keeping records regarding improvements is extremely important, but this task is sometimes overlooked, especially for home improvements. Generally, you need to keep the records of all improvements for 3 years (and perhaps longer, depending on your state’s rules) after you have filed the return on which you report the disposition of the asset.

Gift Basis – If you receive a gift, you assume the doner’s adjusted basis for that asset; in effect, the doner transfers any taxable gain from the sale of the asset to you.

Example: Your mother gives you stock shares that have a market value of $15,000 at the time of the gift. However, your mother originally purchased the shares for $5,000. You assume your mother’s basis of $5,000; if you then immediately sell the shares, your taxable gain is $15,000 – $5,000 = $10,000.

There is one significant catch: If the fair market value (FMV) of the gift is less than the doner’s adjusted basis, and if you then sell it for a loss, your basis for determining the loss is the gift’s FMV on the date of the gift.

Example: Again, say that your mother purchased stock shares for $5,000. However, this time, the shares were worth $4,000 when she gave them to you, and you subsequently sold them for $3,000. In this case, your tax-deductible loss is only $1,000 (the sales price of $3,000 minus the $4,000 FMV on the date of the gift), not $2,000 ($3,000 minus your mother’s $5,000 basis).

Inherited Basis – Generally, a beneficiary who inherits an asset uses its FMV on the date when the owner died as the tax basis. This is because the tax on the decedent’s estate is based on the FMV of the decedent’s assets at the time of death. Normally, inherited assets receive a step up (increased) in basis. However, if an asset’s FMV is less than the decedent’s basis, then the beneficiary’s basis is stepped down (reduced).

Example: You inherit your uncle’s home after he dies. Your uncle’s adjusted basis in the home was $50,000, but he purchased the home 25 years ago, and its FMV is now $400,000. Your basis in the home is equal to its FMV: $400,000.

Example: You inherit your uncle’s car after he dies. Your uncle’s adjusted basis in the car was $50,000, but he purchased the car 5 years ago, and its FMV is now $20,000. Your basis in the car is equal to its FMV: $20,000.

An inherited asset’s FMV is very important because it is used when determining the gain or loss after the sale of that asset. If an estate’s executor is unable to provide FMV information, the beneficiary should obtain the necessary appraisals. Generally, if you sell an inherited item in an arm’s-length transaction within a short time, the sales price can be used as the FMV. A simple example of not at arm’s length is the sale of a home from parents to children. The parents might wish to sell the property to their children at a price below market value, but such a transaction might later be classified by a court as a gift rather than a bona fide sale, which could have tax and other legal consequences.

For vehicles, online valuation tools such as Kelly Blue Book can be used to determine FMV. The value of publicly traded stocks can similarly be determined using Website tools. On the other hand, for real estate and businesses, valuations generally require the use of certified appraisal services.

The foregoing is only a general overview of how basis applies to taxes. If you have any questions, please call this office for help.


Isler Northwest LLC is a firm of certified public accountants and business advisors based in Portland, Oregon. Our local, regional, and global resources, our expertise, and our emphasis on innovative solutions and continuity create value for our clients. Our service goals at Isler Northwest is to earn our clients trust as their primary business and financial advisors.

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Gift and Estate Tax Primer

Gift and Estate Tax Primer

The tax code places limits on the amounts that individuals can gift to others (as money or property) without paying taxes. This is meant to keep individuals from using gifts to avoid the estate tax that is imposed upon inherited assets. This can be a significant issue for family-operated businesses when the business owner dies; such businesses often have to be sold to pay the resulting inheritance (estate) taxes. This is, in large part, why high-net-worth individuals invest in estate planning.

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Tax Treatment of a Room Rental

Tax Treatment of a Room Rental

With the shortage of affordable housing these days, many homeowners are renting out rooms in their homes, providing themselves with some additional cash. Questions that are often raised in regard to room rentals include: Is the income taxable? If so, how is it reported? What deductions are allowed? Can a loss be claimed? Answers to these questions follow.

If a taxpayer rents rooms or other space in a home and the rented portion does not have facilities (a bathroom and a kitchen) that would make it a dwelling unit on its own, the taxpayer and the renter may be considered to be occupying one dwelling unit. Thus, the “landlord” is mixing personal expenses with business expenses, a situation in which the tax code does not permit a loss.

As a result, the income and expenses are treated under the same rules as vacation home rentals and are reported on Schedule E, with prorated expenses deductible against the rental income in a specific order and no loss being allowed.

The deductions are claimed in the following order:

  1. First, mortgage interest and taxes.
  2. Next, operating expenses (examples: advertising, repairs, utilities, maintenance, insurance).
  3. Finally, depreciation.

If the result is a loss, the expenses are only allowed until the income is reduced to zero.

But some unusable expenses may be carried over to the next year, where again they and the next year’s expenses will be limited to the next year’s rental income.

Tax Treatment of a Room Rental
Because the expenses are taken in a specific order, home mortgage interest and property taxes paid for the home (which, for many taxpayers, would be deductible anyway) are first deducted from the rental income. Next come the operating expenses, of which only $1,300 of $1,417 is deductible in this example because that amount reduces the rental income to zero. Thus, $117 of the operating expenses and the depreciation are not deductible.

Any reasonable method for dividing the expenses may be used. The two most common methods for allocating expenses, such as mortgage interest and heat for the entire house, are based on the number of rooms in and square footage of the home.

If you have questions related to renting a room or a vacation home, or about short-term rentals of your home, please give this office a call.