Cross-account tax-lot review that lives in your workflow, not a spreadsheet.

A proposed integration layer for surfacing incomplete inputs and potential wash-sale exceptions across synthetic account data—built for platforms and advisers evaluating a narrower reconciliation workflow.

Share your workflow →Inspect the synthetic output

Not built yet · not tax advice · no filing or accuracy claims

Exception queueSynthetic · 3 accounts

Replacement activityAccount BREVIEW

History coverageJan–DecINCOMPLETE

Source lots2 unmatchedOPEN

Proposed next stepSpecialist review →

01 · THE OPEN PROBLEM

The part every platform has to reconcile.

Broker records may not resolve taxpayer-level activity spanning multiple accounts. That can leave product teams and advisers assembling exports, checking history coverage, and routing ambiguous cases for specialist review.

02 · THE NARROW HYPOTHESIS

Organize exceptions before proposing a tax engine.

Lotline is testing whether teams would pay for an integration layer that identifies missing history, linked-account activity, and unresolved lot relationships—without claiming to determine a tax result.

03 · WHO THIS TEST IS FOR

A deliberately narrow buyer.

FINTECH PRODUCT TEAMS

Portfolio and trading platforms

Exploring a defensible exception workflow before taking on a specialist calculation engine.

ADVISORY OPERATIONS

Firms reviewing active accounts

Mapping how incomplete and cross-account data reaches a qualified tax professional.

TAX WORKFLOW TEAMS

Reporting and reconciliation tools

Testing whether an integration gap remains alongside established specialist software.

Not for: individual tax filing, automated tax conclusions, IRS-compliance claims, or replacing a qualified professional.

04 · SYNTHETIC INTERFACE

The proposed shape of an exception request.

This example is mocked to test workflow usefulness. The endpoint, response, figures, and status labels are illustrative and do not represent completed calculation logic.

POST /research/lots/review
{
  "account_scope": ["acct_1", "acct_2"],
  "history_complete_through": "2026-07-31",
  "transactions": ["synthetic_sample"]
}

RESEARCH RESPONSE
{
  "exceptions": ["replacement_activity_review"],
  "missing_inputs": ["prior_year_history"],
  "status": "specialist_review_needed"
}

05 · FOUNDING RESEARCH

Paid workflow discovery before production logic.

The proposed first engagement maps imports, account linking, exception handling, specialist review, and acceptance criteria. Scope and pricing would be agreed in writing; no fixed SaaS price is represented here.

What is real: a working research site, synthetic workflow examples, and a structured buyer interview.

What is not real yet: a production API, tax determinations, filing output, compliance certification, or customer results.

Required before launch: tax-professional approval of the framing and one paid discovery engagement.

06 · YOUR SIGNAL

Not built yet. Help decide whether it should be.

Tell us what you are building and how you handle this workflow today. That evidence matters more than a generic email signup.