Three installments into this series you've formed an entity, gotten an EIN, and picked up a sales tax Certificate of Authority if you sell taxable goods or services. Installment four is different from the first three in one important way: whether it applies to you at all depends on one thing — the name on your invoice. And if it does apply, the office you walk into — or mail a form to — depends entirely on the choice you made in installment one.

The filing is a Certificate of Assumed Name, what most people call a DBA: paperwork that ties a business name a customer sees on an invoice or a sign back to the real legal person or entity behind it. New York's General Business Law calls that legal identity your "real name" — for a sole proprietor, that's your own name; for an LLC or corporation, it's the exact name on file with the state. The certificate exists so the public, and the courts, can find out who they're actually dealing with when a business trades under something else.

Here's the part that trips people up, and it's written directly into the statute. General Business Law section 130 splits this filing into two completely separate systems depending on what kind of entity is doing the filing. A sole proprietor or general partnership files with a county clerk — a local court office. An LLC, limited partnership, or corporation files with the New York Department of State, in Albany. Same law, same underlying idea, two different governments processing it, two different fee schedules, two very different timelines.

If you're a sole proprietor or general partnership, your paperwork goes to the county clerk in every county where you actually do business. New York City alone has five of them, one per borough: New York County (Manhattan), Kings County (Brooklyn), Queens County, Bronx County, and Richmond County (Staten Island). A contractor working jobs in both Brooklyn and Queens under an assumed name files in both counties — the statute requires a certificate in "each county in which such business is conducted," not just the one where the home office sits. The filing itself is a notarized, one-page certificate, filed in person at the clerk's window or by mail where an office accepts it. Manhattan's own County Clerk publishes a turnaround for mailed filings — 6 to 8 weeks — but none of the five boroughs post an in-person processing time; call your specific clerk's office first if you want to know whether you'll walk out with it done same-day or need to come back.

New York County and Kings County both post the fee directly on their own clerk pages: $100 for the original filing, plus roughly $10 for each certified copy — the same $100 the Department of State collects county-by-county on a corporation's behalf, so sole proprietors, partnerships, and corporations end up paying the same county-level number either way. Bring cash or a card, and call your specific borough clerk first: hours and accepted payment methods vary office to office.

If you formed an LLC or a corporation, skip the county clerk entirely. Your Certificate of Assumed Name goes to the Department of State's Division of Corporations by mail, in Albany, and the fee structure is where a real asymmetry shows up. An LLC or limited partnership pays a flat $25, full stop — the Department's own instructions say plainly there is no county fee for either entity type. A corporation pays that same $25 plus a county-by-county add-on: $100 for each of the five NYC counties it operates in, or $25 per county anywhere else in the state, all collected in the one Albany filing. Standard processing is mail-only, and the state sells expedited handling on top of it — $25 for 24-hour turnaround, $75 for same-day, $150 for two-hour — which tells you plainly that without paying extra, the state filing is the slow leg of this series, not the fast one.

This next part is worth getting exactly right, because a lot of general guidance blurs it: an LLC or corporation does not also have to file anything at a county clerk's office once the Department of State certificate is in hand. The one additional obligation the law imposes runs the other way. General Business Law section 130 requires that a certified copy of the Department of State certificate be "conspicuously displayed" at every job site or office where the business operates under that name. That's a posting duty, not a second filing — frame it, tape it up, keep it visible. You're not making a second trip to a courthouse.

Who doesn't need any of this at all? An LLC or corporation invoicing and contracting under its exact name as filed with the Department of State — nothing added, nothing dropped. A sole proprietor operating under their own true legal name, same rule. Where it gets genuinely tricky is the name that's almost yours: a sole proprietor named John Smith who starts signing contracts as "John Smith Construction" has, under the statute's plain language, created a name other than his own real name. There's no carve-out in the law for tacking your trade onto your own name — the only "add a name alongside your real one and skip the filing" exception on the books applies to corporations, LPs, and LLCs adding a division or trade name alongside their already-filed real name, not to individuals. If your business card, invoice, or truck door says anything beyond your own legal name, plan to file. If you're genuinely unsure whether your specific naming choice crosses that line, that's a short question for your attorney, not a guess you want to make on a public filing.

The reason not to let this one slide is written into the same statute. Miss the filing and later need to enforce a contract signed under the unregistered name, and General Business Law section 130 says you are "prohibited from maintaining any action or proceeding in any court in this state" on that contract "until the certificate required by this section has been executed and filed." It's curable — file the certificate and the courthouse door reopens — but it means a contractor who skipped this step and later needs to sue over an unpaid invoice has to stop, file the DBA, and only then get back in line to collect. Cheap insurance against an expensive, badly timed delay.

So, in order: figure out if you need this at all — true legal name, no filing; anything else added to it, you do. If you're a sole proprietor or general partnership, head to the county clerk in every borough or county where you actually do work with a notarized certificate and $100 per county — call ahead to confirm same-day service, since only Manhattan's clerk publishes a turnaround time and it's quoted for mail, not walk-in. If you formed an LLC or corporation, skip the courthouse — mail the Department of State's Certificate of Assumed Name to Albany with $25 (plus the county add-on if you incorporated), and once it's filed, post the certified copy at every job site or office operating under that name. Either way, get it filed before you sign the contract that name is going to appear on, not after.