The list, and the reason behind each
Cannabis, including CBD in many programs: federally illegal to touch the proceeds of, so the funders' banks will not process it. Adult entertainment and dating: chargeback and reputational rules from the funders' own bank and card partners. Gambling and fantasy sports: the same, plus state licensing. Firearms and ammunition: the funders' bank and investor policies, not law. Payday lenders, debt collectors, debt consolidators: regulatory exposure. Money services — check cashing, currency exchange, money transmission, crypto: anti-money-laundering rules make them unbankable for most partners. Telemarketing and multi-level marketing: fraud exposure. Nonprofits: no owner to guarantee and no revenue in the sense a funder underwrites.
Each funder publishes its own version of the list and they differ at the edges. Vape shops, hemp, tattoo studios, bail bonds, travel agencies and used-car dealers are declined by some and written by others.
Restricted is not the same as declined by a bank
Banks decline whole categories on their own view of risk — restaurants, trucking, construction, gyms, salons, real estate — and those businesses are the core of this market, not its exclusions. The restricted list above is about legality and the funders' banking partners. The bank's list is about a model that does not like lumpy deposits. Being on the second list is why this site exists; being on the first is a different problem.
If you are on the edge of the list
Say exactly what the business does in the application, in plain terms, with the license if there is one. A funder that finds out in underwriting what an application did not say declines for the omission. A funder that knows up front either writes the category or refers you to one that does, and specialist funders exist for most of the edge cases at their own prices. A hemp retailer, a smoke shop or a bail bondsman is not unfundable; they are fundable by fewer funders.