Interior Designer Entity and Estimated Taxes: The Fee-Only LLC, the Designer Who Resells and Needs Books That Separate Two Businesses, the S Election, and the Project Deposit Quarter

The entity question for an interior designer is really a bookkeeping question: a fee-only designer runs one business and can keep it simple; a designer who resells furnishings runs two — a service firm and a retailer — inside one entity, and the books, the bank accounts, and the sales tax account must reflect it. The S election follows fee income past a senior designer's salary, and the estimated tax plan follows the project deposits.

The LLC

A single-member LLC taxed as a sole proprietorship holds the client contracts, the vendor accounts, the insurance, and — for a reselling designer — the sales tax registration and the resale certificate. The liability it isolates is a project gone wrong: a defective installation, a water-damaged floor, a client dispute over a six-figure furnishings order. Professional liability insurance is the first line.

Fee-only or resale: two sets of books

| Element | Fee-only designer | Reselling designer | |---|---|---| | Revenue | Design fees | Design fees plus product sales | | Inventory | None | Goods purchased for resale, deducted as sold | | Client funds | Fee deposits only | Deposits for product — income under the cash method, or client trust funds under the agent model — in a separate account | | Sales tax | None | Registration, collection on goods, installation, unavoidable delivery charges, and design fees that are part of a sale; resale certificate to vendors | | Gross receipts | Fees only | Fees plus the full product price — which can be several times the fees and can cross small business thresholds |

A designer who resells should set up the chart of accounts, the separate client-fund account, and the sales tax account before the first product order, not after the first audit letter.

Is interior design a specified service business?

Interior design is not one of the fields listed as specified service trades or businesses, and design work that delivers plans, drawings, and specifications is not consulting, which the regulations define as advice and counsel — a reasoned position, since no IRS guidance names interior design either way. The deduction is therefore not phased out above 2026 taxable income of $201,750 ($403,500 joint) as a specified service business's would be; above that threshold the W-2 wage limit applies instead. A designer whose engagements are purely advisory, with no design deliverable, is closer to consulting. Product sales are not a service at all; a reselling designer's qualified business income includes the markup.

The S election

Once design fees exceed what a senior designer earns at a firm, the S election saves self-employment tax on the distributions; the owner's salary is benchmarked to that role. Markup income from resale is also business income subject to self-employment tax under a sole proprietorship and distributable under the election. Designers with associate designers and a studio manager on payroll reach the threshold sooner.

Estimated taxes and the deposit quarter

A designer's income arrives in lumps: a design fee deposit at engagement, a large product deposit when the furnishing order is placed, the balance at installation. For a cash-method designer, each is income when received, and the cost of the product is deducted when the goods are delivered to the client — often in a different quarter, and sometimes in a different year. The annualized method on Form 2210 matches estimated payments to the quarters the money lands; a fixed percentage of each fee and markup receipt (not of the client's product deposit, most of which goes to the vendor) moved to a tax account is the discipline — with a larger reserve when a product deposit arrives in one tax year and the goods are delivered in the next, because the whole deposit is taxable in the first year. A designer under the agent model has only fees to reserve against.

Florida's commercial interior design registration

Florida registers interior designers through the Board of Architecture and Interior Design at the Department of Business and Professional Regulation, and residential interior design is exempt from the law entirely. Since 2020 the statute bars only unregistered use of the title "registered interior designer" and requires a registered designer's (or architect's) seal on interior design documents filed for public record, such as commercial permit drawings; the board's own FAQ goes further and says commercial practice requires registration. Registration fees, the 20 hours of continuing education each two-year cycle, and the seal are deductible. Designers whose practice is residential need none of it; those who take commercial work should hold the registration or have a registered designer or architect seal the documents.

Worked example. A designer earns $160,000 in fees and resells $420,000 of product at a 28 percent markup. Her LLC keeps a client-fund account for product deposits, a sales tax account, and a resale certificate on file with vendors. Fees plus markup — about $252,000 before expenses — comfortably exceed a senior designer's salary; she elects S status, takes a $95,000 salary, and distributes the balance. Her two largest projects pay deposits in March and October; she annualizes her estimates and reserves 25 percent of fee and markup receipts as they arrive, leaving product deposits to pay vendors. She takes two commercial projects a year, so she holds Florida's interior designer registration and seals her own permit drawings.

Official sources

The regulation provides: “For purposes of section 199A(d)(2) and paragraph (b)(1)(vi) of this section only, the performance of services in the field of consulting means the provision of professional advice and counsel to clients to assist the client in achieving goals and solving problems.” — Legal Information Institute, Cornell Law School, 26 CFR § 1.199A-5 - Specified service trades or businesses and the trade or business of performing services as an employee., https://www.law.cornell.edu/cfr/text/26/1.199A-5

The Florida Department of Business and Professional Regulation explains: “However, in order to sign and seal interior design documents for permitting purposes, an Interior Designer must register with the Department of Business and Professional Regulation, and obtain a seal pursuant to section 481.221, F.S.” — Florida Department of Business and Professional Regulation, Architecture and Interior Design – FAQs, https://www2.myfloridalicense.com/architecture-and-interior-design/faqs/

The IRS explains: “If you don’t receive your income evenly throughout the year (for example, your income from a repair shop you operate is much larger in the summer than it is during the rest of the year), your required estimated tax payment for one or more periods may be less than the amount figured using the regular installment method.” — Internal Revenue Service, Publication 505 (2026), Tax Withholding and Estimated Tax, https://www.irs.gov/publications/p505

Related guides

• Interior Designer Deductions: The Sample Library, the Software, the Site Visits, the Furniture You Resell at a Markup, and the Sales Tax Florida Expects You to Collect
• Event Planner Entity and Estimated Taxes: The Sole Proprietor Who Should Be an LLC, the S Election Past the Twentieth Wedding, the Deposit Reserve, and the Season That Runs October to May
• What Is an SSTB? Specified Service Trade or Business
• When to Switch to an S Corp, and How the Change Works
• Annualizing Income to Avoid the Estimated Tax Penalty

Next step

Fairlight Accounting handles U.S. domestic, cross-border (U.S.–Canada), and international tax returns, plus bookkeeping, payroll, and CFO advisory. Our U.S. Tax Desk builds the two-business books a reselling designer needs and times the S election to the fee income. See pricing or book a free fit call.