A prewar living room on the Upper West Side, mid-install.

What Running an Interior Design Business in New York Actually Involves

Most of us start a practice because we are good at rooms. Then the calendar fills up with scheduling, paperwork, and negotiations with people who will never once look at the fabric. I run my studio out of Atlanta, where the hardest logistical question on a good day is whether the truck can get down the driveway. New York is a different animal, and every designer I know who works there says the same thing: the building decides.

A residential project in Manhattan usually sits inside a structure with its own rules, its own board, and a very firm opinion about when your installer may use the freight elevator. About 26% of American interior designers are self-employed, according to the Bureau of Labor Statistics, which means most of the profession is running a small business alongside the design work. In New York, that second job is bigger than it is anywhere else.

The license question, and where the real line sits

New York regulates the title, not the work. Anyone can take on residential specification, sourcing, and decorating. Only someone licensed through the state Office of the Professions may call themselves a Certified Interior Designer, and that means an approved degree, two years of supervised experience, and all three sections of the CIDQ exam.

The practical boundary sits somewhere else entirely. Drawings filed with a city agency need the seal of a registered architect or professional engineer. Anything touching egress, structure, gas, or the building's plumbing risers lands on that side of the line no matter what your card says. Plenty of New York designers run whole kitchens and baths without a state certificate. They do it with an architect of record attached to the filing.

Settle that arrangement before anyone signs. If the client is hiring the architect directly, the fee, the schedule, and the question of who actually answers to the board all move.

The alteration agreement is the document that runs your project

New York City has roughly 450,000 occupied co-op apartments and another 318,000 condominiums, together about 22% of the occupied housing stock, per the New York City Comptroller. For a residential designer that is not a housing statistic. It is a statement about who approves your job.

The controlling document is the alteration agreement, and the shareholder signs it, not you. It usually dictates:

• Work hours, generally weekday daytime only, with holiday blackouts
• A refundable deposit against damage to lobbies, elevators, and hallways
• Reimbursement of the building engineer's or architect's review fees
• A completion deadline with per-day penalties after it passes
• Restrictions on wet-over-dry layouts, floor assemblies, and sound attenuation

Review timelines are the schedule risk nobody prices correctly. A board that meets monthly and comes back asking for one round of revisions can add eight weeks before demolition starts. That delay lands squarely on your calendar even though you are not a party to the agreement at all.

What a building wants before anyone touches anything

Certificates of insurance are the gate, full stop. Most managed buildings will not let a delivery crew past the loading dock without a COI naming the corporation, the managing agent, and sometimes the sponsor as additional insureds, at whatever limits the alteration agreement specifies. State rules on business insurance in New York set a floor, and building requirements routinely sit well above it. A designer whose limits fall short loses the install date while a broker reissues paperwork, and that date may be three weeks out.

Employment status matters here too. Nearly every employer in the state carries workers' compensation; sole proprietors with no employees are not required to. Buildings tend not to care about the distinction and ask for a certificate anyway, which catches out solo designers who have never needed one.

Occupied buildings add a further layer. Construction in a building with at least one occupied dwelling unit requires a tenant protection plan covering egress, dust control, debris removal, pest control, noise hours, and keeping heat, water, gas, and electricity running for the neighbors.

When the work needs a permit, and when it does not

A good deal of design work does not. The Department of Buildings treats painting, plastering, resurfacing floors, swapping plumbing fixtures in the same location, and installing new cabinets as work that needs no permit. Move a wall, add circuits, or relocate a drain and you are filing.

The exemption is narrower than it sounds, because unpermitted work still carries licensing. Residential remodeling in the five boroughs generally requires the contractor to hold a Home Improvement Contractor license from the city, which involves an exam, proof of workers' compensation, and either a $20,000 surety bond or enrollment in the agency's trust fund. Hire an unlicensed installer to hang paper or set cabinets and you are in an uncomfortable position if the client later disputes the invoice.

It also wrecks budgets. Trade pricing in the city carries a premium that shows up in ordinary line items, and anyone estimating wallpaper installation cost from national averages will be short before the first roll arrives.

What belongs in the letter of agreement

The letter of agreement carries more weight in New York than the design fee suggests, because projects run long and boards intervene. Describe rooms and deliverables rather than hours. Say plainly what happens when the client adds a room or redraws a floor plan after approvals, because they will.

Procurement terms are where the money actually moves. Custom orders are non-returnable, deposits are usually non-refundable, and lead times stretch. Specify custom rug sizes or hand-knotted goods and you have committed a client to months of production before anything ships. The agreement should record who absorbs a price increase in the meantime. Nearly three-quarters of firms have raised prices to offset rising costs, according to the ASID Trends Outlook for 2026.

Give storage and receiving their own clause. Warehouse fees on a delayed New York install can run for months, and clients almost never expect to pay them.

Sales tax, which is counterintuitive on purpose

Interior decorating and design services are subject to state sales tax throughout New York. Under Tax Bulletin ST-400, services delivered in New York City are exempt from the city's local sales tax and carry only the 4% state rate plus the three-eighths percent Metropolitan Commuter Transportation District tax. Outside the city, the local county rate stacks on top. The city is the cheaper place to deliver the service, which surprises everyone the first time they hear it.

Design fees, furnishings sold to the client, and installation labor can each be treated differently, and a designer buying at trade for resale needs a resale certificate on file. Getting this structure wrong builds a quiet liability that surfaces years later, usually at the worst possible moment.

Trades, sequencing, and who holds the contract

A typical city project runs a general contractor, an electrician, a plumber, a painter, an upholsterer, a fabricator, and a delivery crew. Each one needs its own certificate of insurance filed with the managing agent, and collecting those documents is usually your job even when the client holds the contracts.

Sequencing matters more in old buildings than in new construction, and New York is mostly old buildings. Out-of-square walls and settled floors mean built-in joinery has to be site-measured after demolition rather than ordered off drawings. Release the shop drawings early and you will pay for the remake yourself.

Settle one more thing early: are you contracting the trades or recommending them? Holding the contract brings control of the schedule and responsibility for the outcome. Recommending brings neither. Clients assume otherwise unless the agreement says so in plain words.

When an install goes wrong

Damage in a New York install rarely stays inside the apartment. A scratched elevator cab, a marred lobby floor, or a leak that reaches the unit below becomes a claim against the alteration deposit and then against whoever the board can identify. Boards move fast and have the building's counsel on retainer.

Professional exposure looks nothing like physical damage. A specification error, a misread ceiling height, a fabric that fails a building's flammability requirement, an approval given on the client's behalf without authority: any of these produces a real loss with no broken glass anywhere. That is the category designers underestimate, and it is why firms carry errors and omissions coverage alongside general liability.

Documentation is the defense that actually works. Written approvals on finishes, dated site photographs before and after each trade, and a record of every direction given to a contractor turn an argument about what was agreed into a matter of record.

The constraints are the design

The buildings, the boards, and the filing rules are not obstacles sitting between you and the work. They are the work. They decide what can move, when it can move, how long the schedule really is, and what a fee has to cover to leave anything behind.

The designers I know who run calm New York projects treat the alteration agreement and the letter of agreement as design documents, not administration. The rooms come out better that way, because the constraints were known before the first plan was drawn instead of discovered in month four.