Company matching rules

Deciding whether two company references are the same is the crux of this play — it drives both "still there vs left" and "is the new company already in the CRM?". Company names are noisy; hard identifiers are not. Rank the signals accordingly.

Signal order (strongest first)

1. Domain — normalize both (lowercase, drop scheme, www., path, and port; reduce to the registrable domain, keeping the extra label for known two-part suffixes like co.uk). Equal normalized domains → same company. Explicitly different domains → treat as different unless a LinkedIn page agrees.
2. LinkedIn company page — compare the /company/<slug> slug. Equal slugs → same company (near-certain).
3. Name — only a supporting signal. Normalize before comparing: lowercase, strip punctuation, drop a leading "the", and remove legal/suffix noise (inc, llc, ltd, corp, gmbh, co, holdings, group, technologies, labs, software, solutions, …). Identical normalized names, or one fully contained in the other, is a moderate signal — never enough on its own to justify a CRM write.

Verdict bands

• Match — a hard identifier (domain or LinkedIn slug) agrees. Safe to treat as the same company.
• Ambiguous — only names are similar, or signals partially conflict. This is the "can't confirm" outcome: re-find the LinkedIn URL or flag for review. Do not write.
• Different — domains disagree and nothing else confirms a match. Even a high name similarity does not override disagreeing domains.

Edge cases

• Acquisitions / rebrands / subsidiaries — count as the same company only when domains or LinkedIn pages agree. Matching names across a rebrand without an identifier is "can't confirm".
• Holding companies and DBAs — a shared parent name with different operating domains is different.
• Thin current-employer data — if the new employer came back with only a name and no domain/LinkedIn, a "left" verdict is not confident enough. Fall to "can't confirm".

The principle: earn "confirmed left" from a hard-identified new employer. Prefer leaving a record as "can't confirm" over writing a confident guess.