Tax Basis

A business is taxed on its net income, which is the difference between gross income and expenses. Because a business has many expenses, it has to fill out tax forms listing those expenses in categories, so that the IRS can determine whether the expenses in those categories are reasonable compared to other comparable businesses.

However, many taxpayers earn income from the sale or disposition of assets that are not related to a particular business. Nonetheless, they will have expenses in either acquiring the asset or disposing of the asset, such as sales commissions, sales taxes, and marketing costs. Businesses will also have certain expenses related to particular assets. Tax law permits taxpayers to deduct these expenses indirectly, by adding the expenses to the tax basis (aka adjusted basis) of the asset, which is subtracted from the value received in the disposition of the asset to compute net taxable income.

The tax basis of any asset may be determined by:

When property is converted from personal use to business or income-producing use, then the basis for loss on the converted assets is the lower of the property's adjusted basis or it's fair market value on the date of conversion. However, the gain basis remains the property's adjusted basis on the conversion date, because gain is always recognized whether the property is personal, business, or investment related.

The purchase price of an item is usually the largest component of the basis for most property. State and local taxes, and installation and shipping charges can also be added. If it is a business asset, then any depreciation claimed on the property in prior tax years must be subtracted.

Example — Buying and Selling Stock

You buy $1000 worth of stock and pay your discount broker a $4 commission. You later sell the stock for $1100 and pay another $4 commission to your broker. The $8 of commissions is added to the basis of your stock, giving you a tax basis of $1008. Therefore:

Net Taxable Income = $1100 - $1008 = $92

Of course, since you only actually received $1096 for the sale of your stock, you could have just subtracted your tax basis of $1004 previous to the sale from the sale proceeds to arrive at the same answer.

Often, the tax basis must be adjusted because of improvements to the property or because the property was depreciated. Adjusted basis is the means by which certain expenses for assets can be deducted. Being able to adjust the tax basis because of improvements to the property allows a taxpayer to deduct those expenditures when the property is finally disposed of.

Example — Tax Basis in Real Estate

You paid $120,000 for a house and paid an additional $10,000 to renovate the bathroom. The $10,000 is added to the tax basis of $120,000 to yield an adjusted basis of $130,000. So if you later sell the house for $160,000, then your net income will be $30,000 minus the brokerage commission you paid to sell your house. You can also depreciate your house over 27.5 years. However, because land cannot be depreciated, only the fair market value of the house itself can be depreciated, not the land. However, the total depreciation claimed for the property must be subtracted, adjusting its basis downward, which will increase the amount subject to tax when the property is sold.

Since many assets have a lifetime greater than 1 year, tax law permits individuals or businesses to depreciate such assets over a duration, allowing them to deduct a certain percentage of the property each year until the full cost of the property is deducted. IRC §167

However, if the asset is disposed of before it is fully depreciated, then the taxpayer will have to either report taxable income or take a loss on the property, which will depend on the difference between the sale price and the tax basis of the property at the time of the sale. If the sale price is greater than the tax basis, then there is a net taxable income that must be reported. The income may be taxed as a capital gain or as depreciation recapture, or a combination thereof. If the sale price is less than the tax basis, then the business can subtract that loss from its income. As property is depreciated, its tax basis is decreased annually by the amount of the tax deduction taken on the property. So if the property is fully depreciated, then its tax basis is zero.

Transferred Basis of Gratuitous Transfers

A gift has what is called transferred basis, which means that a gift has the same tax basis as the donor of the gift had. IRC §1015

Inherited property generally has a tax basis equal to its fair market value when the donor died. Often, this is referred to as a stepped-up basis, because assets such as real estate usually appreciate, but some assets do decline in value with age, so the term stepped-up basis is sometimes a misnomer. IRC §1014

This stepped-up basis results from the fact that the property was either taxed as part of the estate or was exempt. The legal rationale for giving estate property a stepped-up basis is that it would be subject to double taxation. However, since there is such a large exemption amount for estates, this is a dubious argument at best. However, property that was inherited from 2010 estates did not receive a stepped-up basis, since there was no estate tax for that year.

Exchanged Basis of Property Exchanges

When taxpayers trade property at arm's length, they tend to trade property of equal value. Hence, the tax basis of the property often has the same tax basis as the property exchanged — what the IRS calls exchanged basis. Substituted basis is a more general term that can refer to either transferred basis or exchanged basis. IRC §7701

When something is received as barter, then the received item has the same tax basis as the bartered item in the same way that an item purchased with cash has a tax basis equal to the amount paid.

When an asset is exchanged for another asset of like kind, the tax basis in the acquired property is the same as the tax basis in the exchanged property, which is called substituted basis. However, substituted basis only applies to like-kind exchanges. For instance, real estate has to be traded for real estate, and tangible property has to be traded for tangible property. If the exchange is not considered of like-kind property, such as exchanging tangible property for intangible property such as a trademark or copyright, then the IRS treats the exchange as a sale of one item followed by the purchase of the other. Nonetheless, the tax basis in the exchanged items would probably be equal in an at-arms-length transaction, since people tend to exchange items of what they considered equal value.

When exchanged items are accompanied by cash payments or a service, then the additional consideration changes the tax basis of the exchanged items. When an item is exchanged for another asset plus cash, then the tax basis of the acquired item is the tax basis of the old exchanged item plus the amount of money that was paid, which is often called boot. If the taxpayer receives an asset plus money, then the tax basis in the asset is equal to the tax basis of the previous owner reduced by the amount of cash paid. If the taxpayer exchanges a good for a service, then the tax basis of the good is equal to the fair market value of the service.

When a personal asset is converted into a business asset, then the tax basis of the converted property is the fair market value on the date of conversion or the adjusted basis in the property, whichever is lower.


Brokerage firms must report to the taxpayer and to the IRS the cost basis, which is the cost of the securities plus brokerage fees, of any securities purchased in 2011 or afterward. Cost basis is equal to the tax basis if there were no other expenses in purchasing the securities. Brokers are required to send Form 1099-B, Proceeds From Broker and Barter Exchange Transactions to the taxpayer to report their calculation of the taxpayer's cost basis.

Individual market transactions must be listed on Form 8949, Sales and Other Dispositions of Capital Assets, then capital gains and losses must be figured on Schedule D, Capital Gains and Losses. The IRS uses a default method of "first-in, first-out" for securities. However, the taxpayer can change this by specifically identifying the securities sold by specifying when they were purchased. If the adjusted basis is incorrectly stated on Form 1099-B, then the taxpayer should notify the broker to have a new Form 1099-B sent, with the correct information. This new reporting requirement will affect mutual funds, exchange traded funds, and dividend reinvestment plans in 2011; other securities will be included in later years.