Can one brokerage see loss lots at another brokerage?

Generally no. A brokerage reports the accounts and transactions in its own systems. The taxpayer must combine records across institutions, and any software alert is only as complete as its connected and current data.

Can a purchase at a different brokerage create a wash sale?

Yes. A loss sale in one account and a purchase of the same or substantially identical security in another relevant account during the 61-day window can create a wash sale. Broker reporting may not identify the cross-institution match.

Do retirement-account purchases matter?

Yes. An IRA purchase can create a wash sale after a taxable-account loss sale. Revenue Ruling 2008-5 indicates that the disallowed loss in that situation does not increase the IRA's basis, making careful household review especially important.

Tax-Loss Harvesting Across Multiple Brokerage Accounts

Multiple brokerage accounts create a coordination problem. Each institution can show its own lots and transactions, but federal tax rules apply to the taxpayer's combined activity. A loss that looks clean on one screen may conflict with a purchase somewhere else.

Build One Household Inventory

Before selling, collect from each relevant account:

security identifier and account owner;
lot acquisition date, adjusted basis, shares, and current value;
year-to-date realized short- and long-term gains and losses;
purchases during the prior 30 days;
scheduled purchases during the next 30 days;
dividend reinvestment, recurring buys, RSU releases, and ESPP dates.

Include taxable accounts and review IRAs and a spouse's accounts when relevant. A consolidated view is a planning control, not a substitute for broker statements or tax forms.

A Cross-Account Wash-Sale Example

An investor sells 100 shares of a fund at an $8,000 loss in a taxable E*TRADE account. Twelve days later, a Fidelity IRA buys 20 shares of the same fund through automatic reinvestment.

The wash-sale analysis is share-matched, so the effect may be partial rather than an automatic disallowance of the entire $8,000. The exact amount depends on the shares and basis involved. Because the replacement is in an IRA, the usual taxable-account basis adjustment may not preserve the disallowed portion.

This is why a precise alert needs share counts, dates, account type, and security—not merely a warning that two tickers appeared in the same month.

Net Gains and Losses Across Institutions

Capital-gain netting occurs on the tax return, not inside a single brokerage dashboard. A gain at Schwab can be offset by an allowed loss at Fidelity, subject to the normal short- and long-term netting rules.

That does not require selling equal dollar market values. Compare realized gain or loss amounts, holding periods, and the purpose of each trade. A loss greater than current gains may become a carryforward rather than an immediate dollar-for-dollar tax saving.

Replacement Exposure

If the investor wants to remain invested, the replacement must fit the allocation and survive a facts-and-circumstances wash-sale review. Compare benchmark, holdings, concentration, fees, liquidity, and risk. Buying the recent winner at another brokerage is not automatically a suitable substitute.

What Consolidated Software Should Show

A useful multi-account tool should:

disclose which institutions, accounts, and transactions are connected;
timestamp the latest successful data refresh;
identify the exact loss lot and possible replacement purchase;
match shares rather than assuming every conflict is all-or-nothing;
separate monitoring, recommendations, and trade execution;
export an audit trail for tax preparation.

It should not claim “no wash sales,” guarantee complete coverage, or present gross realized losses as savings. Missing or stale data can invalidate an otherwise polished alert.

For the broader household design, see tax-loss harvesting across existing brokerage accounts. For selection criteria, use the multi-brokerage software checklist.

Bottom Line

Multi-account harvesting works when the investor consolidates lots, realized activity, and the full purchase calendar before selling. The key advantage of software is coordination and visibility—not a promise that every flagged loss is usable or every cross-account risk is automatically known.