How to Check for Wash Sales Across Accounts

Updated September 26, 2026.

To check for wash sales across accounts, review substantially identical purchases in the 30 days before and 30 days after a taxable loss sale. Include relevant activity beyond the account where you sold, such as a spouse's purchases and purchases in your IRA or Roth IRA. A brokerage tax form may not capture the full picture.

The hard part is often gathering the activity, not understanding that a rule exists. A dividend reinvestment, scheduled contribution or purchase at another institution may be easy to overlook. This guide provides a records checklist for the review; it does not determine whether a particular pair of investments is substantially identical.

What counts as the review window?

Think of a loss sale as the center of a 61-day review period: 30 calendar days before, the sale date, and 30 days after. Looking only forward misses purchases that have already happened. Waiting after a sale does not erase an earlier purchase.

The rule uses “substantially identical,” not merely “similar.” Different securities can share market exposure without automatically answering that tax question, and a different ticker is not an automatic exemption. The IRS describes the determination as depending on facts and circumstances. IRS Publication 550: wash sales

Build an activity map before interpreting the result

Use a worksheet like this for each proposed or completed loss sale. It is a review aid, not a tax calculation engine.

Keep transaction records and confirmations alongside the worksheet. A current holdings snapshot does not show when purchases happened, and a net change in shares can hide purchases and sales that offset each other.

A partial-share example

Suppose an investor sells 80 shares of one stock at a $10 loss per share, for an $800 total loss. Ten days later, the investor buys 20 shares of the same stock in another taxable brokerage account. Assume no other relevant transactions and equal loss per share.

The matched 20 shares correspond to $200 of loss, not automatically all $800. Under the usual taxable replacement-share treatment, that disallowed loss is added to the replacement shares' basis; the remaining $600 is not disallowed by this particular matching event. Other tax facts can still affect the return.

This illustrates why a useful review needs quantities and lots rather than a simple red or green warning. Multiple purchases, unequal lot losses, options and other complications can require a more detailed calculation. The IRS explains matching when share quantities differ. IRS wash-sale examples and basis treatment

Why an IRA purchase deserves separate attention

An IRA or Roth IRA purchase is not simply the taxable-account example with a different label. Publication 550 identifies these purchases in its wash-sale discussion and excludes that situation from the usual replacement-basis adjustment described for taxable shares.

Do not assume a disallowed loss will always be recovered through a later sale. If retirement-account activity is involved, have the specific transaction reviewed. Avoid extending the IRA explanation to every type of tax-advantaged account without a source that addresses that account.

What brokerage reporting does—and does not—settle

Brokerages do report wash-sale information in covered circumstances. It would be unfair and inaccurate to say brokers never track wash sales. The problem is that reporting requirements and the taxpayer's complete obligation are not identical.

Publication 550 describes Form 1099-B reporting tied to covered securities with the same identifier bought in the same account, while also explaining that a loss can be nondeductible even when the form does not report a wash sale. IRS reporting guidance

That distinction matters when transactions span institutions or a household. Reconcile forms with the underlying records rather than using an empty wash-sale field as proof that no issue exists. When a correction or adjustment may be needed, use your preparer and the applicable tax-form instructions.

A practical process before a tax-loss decision

1. Identify the actual lot. Confirm acquisition date, adjusted basis, quantity and account ownership from the institution's records.
2. Gather transaction history. Cover the relevant window and accounts, including automatic activity. Mark unavailable records explicitly.
3. List planned purchases. Review recurring contributions, dividend reinvestments and other known activity that could affect the analysis.
4. Resolve security questions. Separate investment similarity from the tax standard of substantial identity. Escalate uncertain cases.
5. Check investment fit. A tax-motivated change still needs to suit your exposure, liquidity needs and costs.
6. Retain the evidence. Save confirmations and the rationale for the treatment, then reconcile subsequent activity and final forms.

These steps describe the information to review. They are not instructions to cancel retirement contributions, sell holdings or select a particular replacement security. Such choices depend on the household's wider plan.

Where a connected view helps

Mezzi can bring supported accounts into a broader financial picture. It can also incorporate your goals and preferences through AI Personalization, so a conversation can consider more than the visible investment loss. Mezzi capabilities and plans

Use that view to ask better questions: “Which relevant accounts or transaction records are missing from this review?” and “What assumptions would need to be verified before considering a tax-loss sale?” Banking and liability context may also help distinguish a planned tax decision from an urgent need for cash.

Do not assume that connecting accounts gives Mezzi complete tax lots, every spouse transaction, or a certified wash-sale calculation. A missing warning is not a guarantee. Keep institution records and qualified tax review central to decisions that require them.

Make the review repeatable

A small shared record can be more useful than an elaborate dashboard with uncertain coverage. Give each candidate sale a status: records incomplete, tax questions unresolved, decision reviewed, or reporting reconciled. Assign responsibility for the next step.

For choosing a tool to support this process, see the tax-loss harvesting software checklist. The best tool makes missing evidence visible and preserves the details needed to check its work.

Frequently asked questions

Do wash-sale rules apply across different brokers?

Yes. Changing brokers does not by itself avoid the rule. Review relevant substantially identical purchases across accounts, rather than relying only on the selling broker’s report.

Is the wash-sale window only 30 days after a sale?

No. The review includes 30 days before and 30 days after the loss sale. Earlier purchases can matter even if no purchase happens afterward.

Does buying fewer shares disallow the entire loss?

Not necessarily. The IRS provides matching rules when purchase and sale quantities differ. The portion associated with matched shares may be disallowed; detailed lot calculations can be necessary.

Can a connected app guarantee that I have no wash sales?

Do not assume so. Confirm transaction, account and tax-lot coverage, identify missing household activity, and obtain qualified review for uncertain treatment.