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Tax Reporting

The Wash Sale Rule Across Brokers — What Your 1099-B Can't See

Every broker's 1099-B is scoped to that broker alone. If you sell a losing position at Broker A and buy it back a week later at Broker B, neither statement shows the whole picture — but the IRS wash sale rule doesn't care how many accounts you have. It applies across all of them. This is the single most common way a multi-broker investor accidentally overstates a deductible loss.

The rule in one sentence: if you sell a security at a loss and buy the same or a substantially identical security within 30 days before or after that sale — in any account you own — the loss is disallowed for that tax year under IRC §1091.

The 61-day window

The window isn't just "30 days after." It runs 30 calendar days before the sale, the sale date itself, and 30 calendar days after — 61 days in total. A repurchase on either side of the sale triggers the rule, which surprises people who only think to check after they sold.

Example: you sell 50 shares of XYZ at a $2,000 loss on March 10 at Broker A. On March 22, you buy 50 shares of XYZ back at Broker B — a completely different account. That $2,000 loss is disallowed for this tax year, even though the purchase happened somewhere else entirely.

The loss isn't gone — it's deferred

A disallowed wash sale loss doesn't disappear. It gets added to the cost basis of the replacement shares you just bought, which defers the loss until you eventually sell those shares (assuming that later sale isn't itself a wash sale). Get the basis adjustment wrong, and you'll either overpay tax later or understate a future gain — both are real problems if the IRS reconciles your 1099-Bs against each other.

Why a single broker can't catch this

Each broker's 1099-B and cost-basis reporting is legally scoped to activity at that broker. Broker A has no visibility into what you bought at Broker B, so it has no way to flag the wash sale or adjust the basis correctly — that responsibility falls on you (or your preparer) at filing time. The more brokers you use, the more likely this gap actually matters, and the harder it is to catch by scanning statements manually.

Reporting it on Form 8949

A wash sale doesn't get silently dropped from your return — it's reported explicitly. On Form 8949, a wash sale gets code W in column (f), and the disallowed loss amount as a positive adjustment in column (g), which increases your reported gain (or reduces your reported loss) for that specific sale.

What doesn't trigger it. Buying a genuinely different company in the same sector isn't a wash sale — only the same security or one the IRS considers "substantially identical" (generally the same company's stock, not just a similar one). Selling at a gain is never a wash sale; the rule only disallows losses.
Zyvo checks every purchase across all of your connected and imported brokers — not just the one you sold from — and flags wash sales automatically, reported in the correct Form 8949 columns. Try it in the live demo →
Related reading: Stock splits & broker transfers · Average Cost vs FIFO · Best portfolio trackers with tax reporting