The historical cost principle records an asset at the amount actually paid or given up to acquire it, and keeps the record anchored there, so the carrying amount reports a completed transaction rather than an opinion about what the asset is worth now. It is a rule about where a number comes from. Two separate US rulebooks state it, the accounting literature and the tax code, and each does so in a single sentence.
Two Rulebooks, One Rule
The principle is unusual in being stated, in nearly the same words, by two authorities that agree on almost nothing else about measurement.
The accounting literature defines cost as the price paid or consideration given to acquire an asset, and then widens it past the invoice to everything incurred in bringing the item to its existing condition and location. Both layers of that definition, and what they do to a real cost, are set out in cost vs expense.
The tax code reaches the same place in one line, and the shape of that line is the part worth reading.
The basis of property shall be the cost of such property, except as otherwise provided in this subchapter and subchapters C, relating to corporate distributions and adjustments, K, relating to partners and partnerships, and P, relating to capital gains and losses (26 U.S.C. 1012(a)).
The rule occupies the first eleven words and the exceptions occupy the rest of the sentence, which is an honest picture of how the principle behaves in practice. Cost is the default, and three whole subchapters are named as places the default gives way. What that leaves for a particular asset is worked out in depreciable basis.
The Carrying Amount Falls, and Not Because Value Fell
A cost-based balance does move over time, and reading that movement as revaluation is the most common misunderstanding of the principle.
What moves it is allocation. A long-lived asset’s cost is spread across the periods it serves and the spent portion accumulates beside it, so the carrying amount is cost less the cost already charged out, which is a subtraction of history rather than an estimate of price. That mechanism, and the reason a large accumulated balance says nothing about resale value, are set out in accumulated depreciation and depreciated.
For inventory the same separation holds in a different form. A cost flow assumption decides which of the recorded costs move to expense when goods are sold. It does not decide what those costs were, which is why the pool is identical under every assumption and only the split changes, worked through in LIFO vs FIFO.
Where the Principle Stops
It stops wherever a standard puts fair value in its place. A measurement that carries an asset at its current fair value on the measurement date and recognizes the change in the books before any sale takes place is the direct opposite of a cost basis, and the two systems that do this in US practice, one in financial reporting and one in the Internal Revenue Code, are in mark to market.
That is the honest statement of the principle’s reach. It is not a universal rule of US accounting. It is the default measurement, and it gives way wherever a standard decides an estimate of current value is worth what it costs to produce.
The consequence for anyone reading a balance sheet is that equity computed from those balances is a record of amounts paid rather than a valuation of the business, the point developed in book value of equity.
What It Is Confused With
- Sunk cost. Sunk cost is a decision rule about what to ignore going forward. Historical cost is a measurement rule about what to record. The same dollar can be both, and only the decision drops it, which is the distinction in sunk costs.
- Book value. Book value is the output, historical cost less what has been allocated or written off. The principle is the rule that produced it.
- The cost principle. Not confused, the same thing. The two names travel together and neither is more official.
Common Questions
Record what you paid, and report that, rather than what the thing is worth today. The accounting literature defines cost as the price paid or consideration given to acquire an asset, and the tax code says the basis of property shall be its cost.
Yes. Getting the asset into the condition and location it is in counts as part of what was paid for it, so freight, duty and the handling that put the item where it sits belong in the figure rather than in the period.
Because it is verifiable. A price paid is a fact with a document behind it, and a current value is an estimate that has to be produced and defended each period. Where a standard decides the estimate is worth that cost, it displaces the principle and requires fair value instead.
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