US prospecting
Building a B2B prospect list in the USA
The United States has no national business register. Company registration is a state function, so there are fifty of them, and none is built for finding customers. That one absence explains almost everything about American prospecting, including why the data industry there is so much larger than anywhere else.
Checked against the GSA Entity Management API documentation on 22 September 2026. For the rules on contacting the list, see cold email laws by country.
Start from the absence
There is no American Companies House
This is the whole story, and it is worth seeing against the other two markets rather than on its own, because in isolation it just looks like an inconvenience.
| United Kingdom | Australia | United States | |
|---|---|---|---|
| A single national register? | Yes, Companies House. | Yes, the ABN register. | No. Fifty state registers. |
| Industry classification in it? | Yes, SIC codes, filterable. | No. | Only in SAM.gov, which is federal contractors only. |
| Covers unincorporated businesses? | No, incorporated only. | Yes, everyone with an ABN. | Varies by state. |
| Usable to build a list? | Yes. It is your discovery layer. | Partly. It is your verification layer. | No. You buy the company layer. |
So the American build is not a harder version of the British one. It is a different job. In Britain you filter a register down to a list. In Australia you build a list and use the register to verify it. In the United States there is no register doing either, so the company layer itself is something you assemble or purchase, and verification becomes the expensive part rather than the free one.
What is actually free
Four sources, all narrower than they sound
Every list of free US B2B data sources includes these. Few are honest about how little of the market each one reaches.
- SAM.gov. Entities registered to do business with the federal government, so the universe is wrong for most sellers before you start. The public tier does carry NAICS codes and addresses, which is real value. Contact details need a federal system account, and a non-federal user without a role gets ten requests a day. Worth the effort if you sell to government contractors, and not otherwise.
- SEC EDGAR. Public companies only, which is a very small slice of the American market and not the slice most people are selling to. Excellent depth on the companies it does hold.
- IRS filings. Non-profits, and genuinely useful if that is your market, since the filings carry financials and officers.
- State registers. Fifty of them, useful for confirming that a specific company exists and is in good standing, close to useless for building a list across states.
Notice what is missing from that list: any free way to get every private company in an industry, nationally, with a contact. In the UK and Australia that is a public good. In the United States it is a product.
So you are going to buy
Buying well, knowing what you are buying
The reframe that matters: a lot of what you pay a US data vendor for is the absence of a public register, not the presence of insight. That should change the questions you ask.
- Ask about your slice, not the database. A record count in the hundreds of millions tells you nothing about how many usable contacts exist in your industry, in your states, at your company size. Ask for a sample against your real target list before you sign.
- Ask when contacts were last verified. Not when the record was created. Contact data decays fastest in exactly the roles worth selling to.
- Ask what happens to exported data if you leave. The answer differs sharply between providers and it is much easier to ask before signing than after.
- Ask about the contract, not the list price. Annual commitments, seat minimums and credit systems are where the real cost of US data sits.
We have written up ZoomInfo and Apollo in more detail, including the contract questions rather than only the feature ones.
Before you contact it
The US is permissive on sending and specific about the message
CAN-SPAM is an opt-out regime, so you do not need consent before the first email. What you do need is a message that complies, and there is no business-to-business exemption.
The requirements are concrete: do not use false or misleading header information or a deceptive subject line, disclose clearly that the message is an advertisement, include a valid physical postal address, explain how to opt out, keep the opt-out working for at least 30 days, and honour a request within ten business days. The FTC states plainly that the law makes no exception for business-to-business email.
Two cautions this page does not attempt to resolve. State privacy statutes sit on top of the federal rule and vary, and telephone outreach in the United States is governed separately and far more aggressively than email, with a private right of action attached. If you are building a calling programme rather than an email one, take advice specific to it. This page is general information rather than legal advice. The three markets compared puts the US rules beside the British and Australian ones.
Where software helps, and where it does not
What Empiraa Signal does about this
Signal includes a B2B prospect database and enrichment inside the CRM, which in the American context means the company and contact layer you would otherwise buy separately is part of the same system as the pipeline.
What it does not do: Signal does not add your physical postal address to your emails for you, and it will not tell you whether a given US state statute applies to your programme. The unsubscribe is handled, since Signal adds the link, hosts the opt-out page and stops sending to anyone who uses it, but the rest of CAN-SPAM compliance sits with the sender, as it does everywhere.
The prospecting side is at Prospect Spark. The other two markets are at building a list in the UK and building a list in Australia.
Questions people actually ask
US list building, answered
Is there a free US company register like Companies House?
No, and that single absence explains most of what is strange about US prospecting. Company registration is a state function, so there are fifty registers rather than one national one, with different search interfaces, different data and different access rules. There is no federal equivalent of Companies House or the Australian Business Register that you can filter into a prospect list.
Can I use SAM.gov to build a prospect list?
Only in narrow cases. SAM.gov covers entities registered to do business with the federal government rather than all US businesses, so the universe is wrong for most sellers from the start. Its public data tier does carry NAICS industry codes and addresses, which is genuinely useful, but contact details sit behind a federal system account, and a non-federal user without an assigned role is rate limited to ten requests a day. If you sell to government contractors it is worth the effort. Otherwise it is not the answer. The rate limits, documented.
What are the genuinely free US B2B data sources?
Fewer than the listicles suggest. SEC EDGAR for public companies, which is a very small slice of the market. SAM.gov for federal contractors, with the limits above. IRS filings for non-profits. State registers, one at a time, for corporate status rather than targeting. Every one of these is narrow, and none of them gives you a national list of private companies by industry with contacts attached, because no such free thing exists in the United States.
Why is US B2B data so expensive compared with other markets?
Because you are buying something other countries publish. In the UK, Companies House gives you every incorporated business with industry codes, free. In Australia, the ABN register gives you every business with its entity type, free. The United States publishes no equivalent, so the company layer that is a public good elsewhere is a product there. That is worth knowing when a vendor prices on the size of their database: a lot of what you are paying for is the absence of a register rather than the presence of insight.
Is cold email to US businesses legal?
Yes, and it is the most permissive of the three markets on sending, because CAN-SPAM is an opt-out regime rather than a consent one. It is also the most specific about what the message must contain: identify it as an advertisement, include a valid physical postal address, no deceptive subject lines, and honour an opt-out within ten business days. There is no business-to-business exemption, which the FTC states in terms. The FTC compliance guide.
How does building a US list differ from a UK or Australian one?
In the UK you filter the national register down to a list. In Australia you build the list elsewhere and use the national register to verify it. In the United States there is no national register to do either with, so the company layer has to be bought or assembled, and verification is the hard part rather than the easy one. Same job, three different shapes. The three compared.
Question not answered here? Ask ANI and get a straight answer.
Show your working
Sources
Checked against these on 22 September 2026. This page is general information rather than legal advice.
- GSA, SAM.gov Entity Management API for the data tiers, the NAICS codes in the public tier, the federal system account requirement for contact details, and the ten requests per day limit for a non-federal user without a role.
- SAM.gov entity information for what entity registration covers.
- FTC, CAN-SPAM Act compliance guide for business for the message requirements, the ten business day opt-out deadline and the absence of a business-to-business exception.