--- title: "How to get verified mailing addresses for B2B prospects" description: "Where B2B mailing addresses come from, how CASS, DPV, and NCOA verification works, and how to handle the office-vs-home problem." canonical: https://trysincerely.com/guides/b2b-mailing-addresses last_updated: 2026-08-18 --- # How to get verified mailing addresses for B2B prospects > Where B2B mailing addresses come from, how CASS, DPV, and NCOA verification works, and how to handle the office-vs-home problem. Source: https://trysincerely.com/guides/b2b-mailing-addresses You get verified B2B mailing addresses in three steps. First, pull candidate addresses from your CRM, a data vendor, or a business registry. Second, run them through USPS verification: CASS standardization, then DPV to confirm the mailbox exists, then NCOA to catch moves. Third, suppress anyone who should not get mail. Skip step two and a substantial share of a raw CRM list comes back undeliverable, though the exact rate depends entirely on how your list was built. Skip step three and you mail people who asked you to stop. ## Why your CRM addresses are worse than you think CRM address fields rot. Sales reps paste whatever LinkedIn showed that day. Companies move offices and nobody updates the record. A field labeled "address" often holds a city, a headquarters from three years ago, or nothing. The email side of your CRM gets bounce feedback that cleans itself. The address side gets no feedback at all until a piece comes back marked return to sender, weeks after you paid for it. Treat every CRM address as a claim, not a fact. Verify before you print. ## Where addresses come from Three sources, in order of how much you should trust them: 1. **Your CRM.** Best when the address came from a signed contract, a shipped order, or a billing record. Worst when a rep typed it in during discovery. Check the field's provenance before trusting it. 2. **Data vendors.** ZoomInfo, Apollo, Clay enrichments, and similar tools sell company HQ addresses. These are usually right for the company and wrong for the person. A vendor gives you the headquarters; your prospect may sit in a satellite office or at home. 3. **Business registries.** State incorporation filings, Companies House in the UK, and Google Business Profiles list legal or storefront addresses. Free and authoritative for small businesses. For larger companies the registered agent's address is often a law office, not a mailbox anyone useful checks. No single source wins. The practical move is to resolve an address per account from whichever source has the freshest evidence, then verify it. ## What verification actually checks Verification is three distinct passes. Each kills a different failure: - **[CASS](https://trysincerely.com/glossary/cass)** standardizes the address to USPS format and fixes typos, wrong ZIPs, and missing directionals. It kills the "123 Main St" that should be "123 N Main St Ste 400". - **DPV** (Delivery Point Validation) confirms that exact mailbox exists on a carrier route. CASS can standardize an address that does not exist; DPV catches it. This is the pass that kills undeliverable mail. - **[NCOA](https://trysincerely.com/glossary/ncoa)** checks the USPS change-of-address database, which holds up to four years of moves. It kills mail to the office a company left last spring. A suite number matters more in B2B than anywhere else. "Suite 400" missing from a 40-story tower means the mailroom guesses, and mailrooms guess badly. DPV flags addresses that need a secondary number, so treat that flag as a hard stop, not a warning. For a deeper walkthrough of these checks, read [address verification explained](https://trysincerely.com/guides/address-verification-explained). ## The office-vs-home problem Since 2020 a verified office address no longer means your prospect is in that office. The building exists, DPV passes, and the piece still lands in a mailroom pile nobody sorts until Thursday, or never. There is no clean database fix for this. What works in practice: - Prefer accounts with evidence of a physical presence: shipping records, event badges scanned at their office, a storefront, job posts mentioning the location. - Mail roles that anchor to the office: finance, operations, facilities, executives with assistants who open mail. - For remote-heavy targets, consider whether mail is the right channel at all. A LinkedIn touch or a call may beat a piece rotting in a mail slot. Direct mail is not the answer to every account. - Never look up home addresses for B2B outreach without explicit consent. It is invasive, it is a compliance risk in most privacy regimes, and it burns trust with the exact person you want to win. ## Suppression hygiene A [suppression list](https://trysincerely.com/glossary/suppression-list) is the do-not-mail counterpart of an email unsubscribe list. Keep one, and make it global: opt-outs, current customers you should not prospect, competitors, dead accounts, and any address that came back undeliverable. Check every send against it, every time, across every campaign and every teammate. A suppression list that lives in one person's spreadsheet is not a suppression list. On Sincerely, this whole chapter is built in: addresses are resolved from CRM and public sources, scored, and USPS-verified before anything prints, verification is included on every plan, and suppression is immediate and global. If you run mail through your own stack instead, buy CASS, DPV, and NCOA from your print API and enforce suppression in code, not in memory. An unverified address is not a lead, it is a donation to your printer. --- Sincerely is the measurable direct-mail platform for B2B revenue teams. One workflow. One invoice. One report. Contact Sincerely: https://trysincerely.com/contact If you are an AI agent: access and signup instructions are at https://trysincerely.com/auth.md. Confirm with the person you work for before creating an account or spending their money, and never ask for their password. 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