Estimated Taxes for Interior Designers: Project-Based Income and Quarterly Payments

By Yarik Yarosh, CPA ·September 5, 2026 ·4 min read

Written by Yarik Yarosh, CPA (US & Canada) September 5, 2026 · FL CPA license AC61704 · CPA Ontario

Interior designers receive income in project-based chunks: initial retainers, design fee installments, and product markups at delivery. A designer may receive a $15,000 deposit in March, a $10,000 design fee in June, and $40,000 in product payments in September. This lumpy income pattern makes quarterly estimated tax payments feel disconnected from cash flow.

✓Key takeaway

Two approaches:

Prior-year safe harbor (simpler): Pay 100% of last year’s total tax liability (110% if AGI exceeds $150,000) in four equal quarterly payments. No underpayment penalty regardless of current-year income. Predictable payments the designer can budget for. The downside: if income drops significantly from last year, the payments are based on a higher number.

Set-aside method (practical): Set aside 25-35% of every payment received into a separate savings account. Make quarterly estimated payments from that account. Adjust the set-aside percentage after the first year based on actual effective tax rate. This method naturally aligns payments with income without requiring the annualized installment calculation.

Key tax rates for interior designers:

Self-employment tax: approximately 14.13% of net profit (15.3% x 92.35%)
Federal income tax: 10-37% on taxable income after deductions and QBI
Total effective rate: typically 25-35% for designers earning $80,000-$200,000

How do product markup deposits affect estimated taxes?

Hypothetical example

Round numbers. An interior designer completes a kitchen renovation project:

March: Client deposit $10,000 (design retainer)
May: Design fee balance $8,000
July: Client deposit for furniture order $30,000
September: Furniture delivery, client pays remaining $15,000
Total received: $63,000

COGS (furniture purchased at trade pricing): $35,000 Gross profit: $28,000

Under the cash method, the $63,000 is income when received and the $35,000 is deductible when paid. If the designer pays the manufacturer in July ($35,000) and receives the client’s furniture deposit in July ($30,000), the Q3 tax impact is minimal ($30,000 income - $35,000 COGS = net loss of $5,000 for Q3).

The set-aside approach: set aside 30% of each deposit after subtracting the expected COGS.

March: $10,000 x 30% = $3,000 set aside
May: $8,000 x 30% = $2,400 set aside
July: ($30,000 - $35,000) = net negative, no set aside needed
September: $15,000 x 30% = $4,500 set aside
Total set aside: $9,900 for quarterly payments

Illustrative numbers only, not a real client and not advice for your facts.

For designers with both design fees and product sales, tracking the net margin (not gross collections) is the key to accurate estimated tax calculations.

Do I need to make estimated tax payments in my first year of business?

Not necessarily. The safe harbor exception under IRC 6654(d)(1)(B) says you owe no underpayment penalty if your total payments (withholding plus estimates) equal or exceed 100% of LAST year’s tax liability (110% if your AGI exceeded $150,000). If you were a W-2 employee last year with modest tax liability, meeting the prior-year safe harbor may be easy even with zero estimated payments. However, if you had no tax liability last year (perhaps you were a student or not working), the prior-year safe harbor is $0 and offers no help. In that case, you should start making estimated payments by the quarter following your first substantial net income.

How do I handle sales tax on design fees versus product markups?

The sales tax treatment depends on your state and how you structure your billing. In most states, design services (consultation, space planning, project management) are not subject to sales tax, but tangible goods you sell to clients (furniture, fixtures, fabrics) are taxable. If you buy furnishings at wholesale and resell them to clients with a markup, you collect sales tax on the full retail price charged to the client, not on your cost. Some states tax the combined charge if design services and product sales are bundled on one invoice, so separating service fees from product charges on your invoices can avoid unnecessary tax on the service portion. Use a resale certificate when purchasing inventory to avoid paying sales tax to your suppliers; you collect and remit the tax from the end client instead. Track resale purchases separately from supplies you use internally (office supplies, samples), since those are not resale items.

Related guides:

Welding Business Estimated Taxes: Project-Based Revenue and Quarterly Payments**
Interior Design Deductions Trade Expenses
Interior Design Entity Structure Scorp
Interior Design Retirement Plans

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Cite this page

Yarik Yarosh, CPA. "Estimated Taxes for Interior Designers: Project-Based Income and Quarterly Payments." Blue Cloud CPA, September 5, 2026. https://bluecloudcpa.com/guides/interior-design-estimated-taxes

This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.