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Identify the tax lot before the broker deadline16 minute read
Which shares are sold after covered call assignment?
Learn how covered call assignment selects stock tax lots, when specific identification matters, and how basis and holding period affect the result.
Direct answer
Covered call assignment requires delivery of the contract's share quantity, but it does not by itself choose the investor's preferred tax lot. The shares treated as sold depend on a valid specific-lot instruction or the method applicable when no lot is adequately identified. Check the broker's assignment-lot workflow and deadline promptly, because cost basis and holding period can materially change the reported gain or loss.
Contract delivery and tax-lot selection answer different questions
A standard equity call usually controls 100 shares, so assignment of one covered call generally sells 100 shares at the strike. OCC deliverable adjustments, partial assignment, or multiple contracts can change the quantity. The clearing obligation concerns delivery of fungible shares; it does not preserve the writer's favorite purchase date or cost basis.
Tax-lot selection answers which acquisition record supplies basis and holding period for the shares disposed of. A broker may display shares as called away before showing the final lot allocation. Do not infer the tax lot from the shares that appeared to cover the call when it was opened.
Specific identification requires a timely documented instruction
IRS Publication 550 says that when a broker holds the stock, adequate identification generally requires telling the broker the particular shares to sell or transfer at the time of the transaction and receiving written confirmation within a reasonable time. A standing disposal method may guide the broker, but confirm how the firm applies it to option assignment.
If shares cannot be adequately identified, the IRS general rule uses the basis of the shares acquired first. Broker screens can offer FIFO, LIFO, highest-cost, or tax-sensitive choices, but availability and assignment deadlines are firm-specific. A preference saved after the firm's cutoff may not change the completed allocation.
The selected lot changes basis and holding period
Assume 100 shares bought at 40 and another 100 bought at 55, followed by one 50-strike covered call assignment. Before premium and fees, selecting the 40-basis lot produces a 1,000 stock gain; selecting the 55-basis lot produces a 500 stock loss. The call premium generally increases amount realized under U.S. federal rules.
The selected lot also determines whether the stock result is short- or long-term. Qualified-covered-call, straddle, wash-sale, and holding-period rules can modify the apparent result. A highest-cost choice is therefore not automatically the best tax choice, and tax results outside the United States can differ.
Reconcile the allocation before the correction window closes
After assignment posts, record the contract multiplier, assigned contracts, delivered shares, strike, premium, stock lots, acquisition dates, adjusted basis, and broker confirmation. Compare the tax-lot page with the assignment activity rather than relying only on the reduced position total. For partial assignment, verify both the shares sold and the calls still open.
If the displayed allocation is wrong or pending, contact the broker's options or cost-basis team immediately and ask for its assignment-lot cutoff and written confirmation. Do not assume a later tax-report edit recreates a timely identification. Preserve the original instruction and any correction, then consult a tax professional when the amount or holding-period treatment is material.
Common questions
Does a covered call automatically sell my oldest shares?
Not always operationally, because a valid specific-lot instruction or broker workflow may select another lot. Under the general U.S. federal rule, however, shares acquired first supply basis when the shares sold cannot be adequately identified. Confirm both the firm's assignment process and the final written lot record.
Can I choose the highest-cost shares after assignment?
Possibly, but only within the broker's process and deadline, and a late screen change may be ineffective. Ask when the firm treats assignment as the sale or transfer for lot-selection purposes and obtain written confirmation. Highest cost may reduce current gain, but holding-period and special option rules also matter.
Does opening a covered call lock specific shares to the contract?
Usually not for tax-lot purposes. Coverage shows that the account has sufficient deliverable shares, while lot identification determines the basis record used when shares are sold. Restrictions, pledged shares, employee stock, adjusted contracts, or broker-specific systems can require additional review.
What happens when only some covered calls are assigned?
Only the assigned contracts create the corresponding stock sale, based on each contract's actual deliverable. Verify which lots supplied those shares and which short calls remain open. Do not multiply blindly by 100 when corporate actions have adjusted the contract.
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