Tax Lots And Which Shares You Actually Sell

Selling part of a holding built up over many years raises a question that has nothing to do with the market: which of the accumulated purchases is being sold. The answer changes the reported gain.

A holding is a collection of separate purchases

Each purchase creates a tax lot with its own date and its own cost. A position built through regular contributions may contain hundreds of them.

The shares themselves are identical and interchangeable, but for tax purposes the lots are distinct because their costs differ.

Selling a portion therefore requires a rule to determine which lots the sale draws from, since the shares cannot identify themselves.

Identification methods produce different results

Common approaches include treating the earliest purchases as sold first, averaging the cost across all holdings, or specifically identifying chosen lots at the time of sale.

Selling the oldest lots in a long-held position generally realises the largest gain, because those shares were usually bought at the lowest prices.

Specific identification allows the seller to choose lots with higher costs, which produces a smaller reported gain from the same sale proceeds.

The method is often set by default

Brokers apply a default method unless instructed otherwise, and that default is applied automatically to sales that arrive without instructions.

Changing the method or identifying specific lots generally has to happen at or before the trade, not afterwards when the consequences become visible.

Which methods are permitted, and whether an election can be changed, differs by jurisdiction and by asset type, and the rules are revised over time.

Holding period travels with the lot

Where a system distinguishes between gains on assets held for longer or shorter periods, that classification attaches to each lot individually.

A sale can therefore produce a mixture of classifications from a single instruction, depending on which lots it drew from.

This is one reason automatic reinvestment of distributions complicates matters, since each reinvestment creates a new lot with a fresh date.

Records are the binding constraint

Lot-level history depends on records held by the broker or the investor, and transfers between providers do not always carry that history intact.

Where cost information is lost, reconstructing it from old statements is possible but laborious, and gaps can force unfavourable assumptions.

Keeping transfer paperwork and confirming that lot detail arrived at the receiving provider is the step that prevents that situation from developing.