Find hard-to-locate company tax IDs and addresses with GPT-5 Pro

Our rewrite with extra checks. The poster didn't test it.

Goal: Find FEINs and addresses for these companies using high-quality sources only.

Inputs (fill in or confirm):
- Company names and states
- Any known identifiers
- Why I need them (vendor setup, research)
- Output format (spreadsheet columns)

Rules:
- Use SEC filings, IRS Form 990s, state registries or official documents.
- Record the source link for each FEIN and address.
- Match the exact legal entity.
- Mark uncertain matches.
- Prefer the most recent filing and note its date.
- Distinguish parent and subsidiary entities.
- Never use paid or scraped databases without telling me.
- Use official sources first: state business registries, SEC filings, IRS lists or the company's own documents.
- Mark confidence for each result; leave blank rather than guessing.
- Flag companies with similar names and how you told them apart.
- Double-check each ID format (e.g. nine digits).
- Explain how you found each hard case in one line.

If you get stuck: If no reliable source exists, say so. If a login, CAPTCHA or two-step code appears, stop and ask me to handle it; never guess or store passwords.

Verify before you finish: Re-open each source to confirm.

Output: Table: company, FEIN, address, source.

Done when: every result has a reliable source.