Most landowners pay more federal and state tax on their timber sales than they have to — because they never established and tracked their timber basis. Basis is the single most leveraged tax document on a timber tract. Done at acquisition, it costs a small fraction of what it saves over the life of the ownership. Skipped at acquisition, it can cost the landowner thousands of dollars per cruise on every future sale.
This Field Note covers what timber basis actually is, how to allocate it at acquisition, how to track it over time, and what to do when basis was never established.
What Basis Actually Means
Tax basis is what the IRS treats as the landowner's investment in an asset. On a timberland tract, the property's total basis — purchase price or stepped-up inheritance value — is split between three separately tracked assets:
- Land basis. The bare land portion of value, not depleted.
- Timber basis. The standing timber portion of value, recovered through depletion as timber is sold.
- Improvements basis. Roads, buildings, and other capital improvements, depreciated or capitalized per their own rules.
Without the allocation, the IRS default treatment can effectively leave the landowner with zero timber basis — meaning every dollar of timber sale gross becomes taxable gain, with no depletion deduction available to recover what was actually invested.
When Basis Gets Established
The three events that set timber basis:
- Purchase. Basis is the purchase price (plus acquisition costs) allocated between land and standing timber based on relative fair market values at the date of purchase.
- Inheritance. Stepped-up basis at fair market value on the date of death, allocated between land and standing timber. Covered in stepped-up basis on inherited timberland.
- Gift. Carryover basis from the donor, allocated under the donor's existing schedule. Covered in stepped-up basis vs. carryover basis.
How Allocation Actually Works
A defensible basis allocation includes:
- A cruise of the standing timber at the acquisition date, by species and product class.
- Stumpage values at the acquisition date by product class, sourced from regional market reports.
- A stand-by-stand valuation reconciling the cruise to a defensible timber value.
- A land value based on comparable land sales for the area, often supported by a real estate appraisal.
- A written allocation dividing the property's total basis between land and timber by relative fair market value.
The combined documentation is what the IRS or a future auditor reads. A registered forester produces the timber side; a real estate appraiser or land valuation produces the land side; the CPA reconciles the allocation onto the return.
The Depletion Schedule
Once basis is established, it has to be tracked. The depletion schedule maintains, by year:
- Original timber basis at acquisition.
- Original cruise volume by product class.
- Basis per unit (per ton, per MBF, per cord) for each product class.
- Units sold each year by product class, with depletion taken.
- Capitalized additions (reforestation, planting cost, certain improvements).
- Adjusted current basis.
The depletion deduction on a sale is calculated as the basis per unit multiplied by the units sold. That deduction reduces the taxable gain. Without the schedule, the landowner usually takes no depletion — which means the full sale proceeds become taxable gain.
Growth and Basis
Timber that grows after acquisition does not increase basis. The volume cruised at acquisition is the basis volume; new growth is treated as having zero basis. This is why depletion is calculated against the original cruise volume rather than against current standing volume, and why old tracts with strong post-acquisition growth still get meaningful depletion against the legacy basis.
Casualty Adjustments
A casualty event — hurricane, tornado, wildfire — that destroys standing timber can be claimed as a casualty loss against the timber basis. The deduction reduces remaining basis. The casualty appraisal is a separate registered-forester product and is covered in salvage timber sales after storms.
Form T and Basis Reporting
IRS Form T (Forest Activities Schedule) is where timber basis, depletion, and timber transactions are reported. Filing Form T is the documentation that supports the depletion deduction on the return. Many tax returns omit Form T and the depletion deduction together. Covered in more detail in timber taxation basics for Mississippi and Alabama landowners.
What to Do If Basis Was Never Established
Two options, in order of preference:
- Retrospective allocation. A registered forester reconstructs the standing timber value at the original acquisition date using historical market data, comparable timber sales from the period, and a backward-projection of the current cruise. The CPA files an amended return or adjusts the schedule going forward. Weaker than a contemporaneous allocation but defensible when properly documented.
- Forward establishment at the next acquisition or transfer event. If the property is going to pass to heirs, structuring the estate so a clean stepped-up basis is established and documented at that point is sometimes the best available path.
Real-World Pattern
A common Mississippi situation: a tract bought in the 1990s with no basis allocation at the time. The landowner sold timber three or four times over the years, paying tax on the full proceeds each time because no basis was ever established and no depletion was taken. A retrospective basis allocation by a registered forester — supported by historical regional stumpage data and a current cruise rolled back to the 1990s acquisition date — establishes a defensible basis. Going forward, every future sale claims depletion. The retrospective work, plus the depletion schedule maintenance, pays for itself on the next sale and beyond.
Where Basis Work Pays Off Most
Long-held tracts in the Pine Belt and east-central Mississippi (Jones, Newton, Lauderdale) and across west and central Alabama frequently have decades of un-claimed depletion sitting on the table. Inherited tracts where the stepped-up basis was never properly allocated at the time of death are the most common pattern. Establishing basis now — even retrospectively — typically pays for itself on the next sale.
The Right Sequence
Basis allocation at acquisition is one of the few financial decisions on a timberland tract where the right move costs little and the payoff stretches across the entire ownership. Help producing the timber-side documentation — cruise, valuation, written allocation — is part of the work covered under our timber appraisal practice, and ties directly into the basis-tracking conversation a timber-aware CPA runs on the return.