Should I mark up furniture or charge a design fee only? A solo interior designer's guide to fee models

Every solo interior designer I talk to eventually hits the same wall. A client asks why the sofa on the invoice is $4,200 when they can see it on the manufacturer's B2B portal for $2,800. The answer is not "because I marked it up." The answer is "because we agreed on this fee model in the contract, and here is what it pays for." If you cannot say that sentence with a straight face, your fee model is wrong for how you actually work.

This piece walks through the three fee structures solo studios use in 2026, runs the same $60K living room through each P&L, and gives you the language for the trade-cost conversation before it happens.

What are the three fee models solo interior designers actually use?

The three durable models are cost-plus markup, flat design fee with net trade pricing passed to the client, and monthly retainer plus a procurement fee. Each one bills the same underlying labor and product cost differently. The client's out-of-pocket lands within roughly 10% across all three on a full-service project.

Cost-plus markup is the legacy model. You buy at trade (usually 40-50% off MSRP depending on the vendor), then mark up to the client at a rate you disclose in the contract. The 2023 ASID Compensation and Benefits Report puts the most common designer markup band at 20-35% over net trade, though senior studios routinely charge 40%. Your revenue on product scales with the size of the specification.

Flat design fee with net trade is the transparency-forward model. You quote a fixed dollar design fee upfront (or hourly with a not-to-exceed), then pass every product through at your net trade cost with the invoice attached. The client sees exactly what you paid. Your revenue is decoupled from product volume, which is either a feature or a bug depending on your business.

Retainer plus procurement fee is the model that shows up on larger residential jobs and on trade-heavy commercial work. The client pays a monthly retainer (typically $3,000-$8,000 for a solo studio) for design services, and you charge a 10-15% procurement fee on top of net trade to cover the operational cost of ordering, tracking, receiving, and installing. It looks like consulting plus a small logistics markup.

None of these is inherently more ethical than the others. The Business of Home columns from Sean Low have been making this point for a decade: the ethics live in the contract clarity, not the model choice. What actually differs is the cash-flow timing, the incentive alignment between you and the client, and how each model handles a project that goes over scope.

How does cost-plus markup work for interior designers, and what margin should I expect on a $60K living room?

For interior designers, cost-plus markup means you charge the client MSRP or a defined multiplier over your net trade cost, and the spread is your revenue on product. On a $60K MSRP living room bought at an average 40% trade discount, your net cost is $36K. At a 33% markup over net, your revenue on product is roughly $12K. Add a $3,500 initial design fee and you are at $15,500 gross on the project.

Here is the P&L broken out.

The cash-flow shape is the interesting part. Under cost-plus you typically collect 50% deposit on product at spec approval and 50% at delivery. That means you are holding client funds for the ordering cycle (often 8-16 weeks on custom upholstery), and you carry vendor-side exposure if a client backs out mid-order. Your operating account swings hard. On a $51,500 project you might see $25K land in your account in month one, then $0 for two months, then another $25K on install.

The upside of cost-plus is that your revenue scales with the client's ambition. If the client upgrades from the $8K sofa to the $14K sofa, your take goes up automatically without a fee renegotiation. The downside is the moment the client Googles the sofa. If they find it on Perigold or a to-the-trade site with a lower price, the conversation you have to run is defensive by default. More on that below.

One thing to watch: some vendors now enforce Minimum Advertised Price (MAP) policies that constrain what the client sees online, while others (RH, Crate & Barrel, Restoration Hardware) publish direct-to-consumer pricing that is often within 5-10% of your trade cost after their frequent sales. The pool of vendors where a 33% markup is defensible against a Google search is shrinking every year. This is the structural reason the flat-fee model has been gaining share since 2020.

How does a flat interior design fee with net trade pricing compare on the same $60K project?

For interior designers, a flat design fee with net trade means the client pays a fixed design fee upfront and then pays your actual trade cost on every product with the vendor invoice attached. On the same $60K MSRP living room bought at $36K net trade, you might charge a $15,000 flat design fee. The client's total out-of-pocket is $51,000, almost identical to cost-plus, but your gross is now $15,000 in fee revenue plus zero on product.

The P&L looks like this.

The cash-flow shape is different in a way that matters. Under this model the design fee is usually billed 50% at contract signing, 25% at spec approval, 25% at install. That $15K lands in three predictable chunks tied to your labor calendar, not the vendor ordering cycle. You are not floating product money. If the client cancels an order mid-project, you have already earned most of your fee for the work you did, and the client eats the vendor restocking fee directly.

The pitch to the client is simple and it holds up under scrutiny. "You are paying me for my time and taste. Product goes through you at what I pay. I will send you every vendor invoice." Business of Home has documented this model expanding rapidly among solo studios under 40 who came up in the era of visible pricing. The Decorilla and Havenly-style online marketplaces have trained consumers to expect design work billed as a distinct service line, and the flat-fee model reads naturally to those clients.

Where this model breaks down: on projects with heavy custom specification, sourcing time expands unpredictably. If you quote $15K flat and end up doing 180 hours of sourcing on a difficult custom bed with a fabric that keeps going out of stock, your effective hourly rate collapses. Most designers who run this model add a not-to-exceed hours clause with hourly billing over the cap, typically at $200-$275/hr for a solo studio in a top-10 metro.

The itemized deliverable becomes load-bearing under this model, because the client is going to see every line. Which brings us to what that document actually looks like.

How does a retainer plus procurement fee model change an interior designer's P&L and cash timing?

For interior designers, retainer plus procurement fee bills a fixed monthly retainer for design work and adds a 10-15% procurement fee on top of net trade for the operational cost of running product through your account. On a $60K MSRP living room delivered over four months, that looks like a $4,000/month retainer for four months ($16,000) plus a 12% procurement fee on $36K net trade ($4,320). Gross to studio: $20,320.

The P&L breakdown.

On paper this is the highest-grossing of the three models on this project. The cash flow is also the smoothest. You bill the retainer on the 1st of every month regardless of where any given vendor lead time sits. If a Verellen sofa slips from 12 to 20 weeks, your income does not slip with it.

The catch is that retainers are the hardest model to sell to a first-time residential client. Homeowners understand paying for product and paying for a project. They struggle with paying $4K a month with no immediate deliverable in the first 30 days. This model works best when (a) the client has bought design services before, (b) the scope is genuinely multi-room or ongoing, or (c) you are anchored in commercial or hospitality work where retainer billing is the default.

Retainer plus procurement fee also aligns your incentives with the client's operational reality. You get paid for the sourcing hours, the vendor calls, the delivery coordination, and the punch-list follow-up that eat most of a solo interior designer's week and are invisible under cost-plus. The 12% procurement fee is not markup in the traditional sense. It is a defined operational overhead line. When a client asks "what is the 12% for?" the answer is a list of concrete tasks: placing POs, tracking freight, receiving at the warehouse, coordinating white-glove delivery, running punch. HFA and AHFA trade norms both acknowledge procurement handling as a distinct cost center that must be recovered somewhere.

One structural risk: retainers create pressure to keep the meter running. Clients notice if the project could have wrapped in three months but ran five. If you use this model, publish a clear scope and a defined end-date, and be willing to pause the retainer when you are legitimately blocked on a client decision.

Which fee model should I pick for my interior design studio in 2026?

Interior designers should pick cost-plus if your client base is not price-shopping vendors and your project sizes are consistently over $80K in product spend. Pick flat design fee with net trade if you compete for design-savvy clients who read Business of Home and your project scopes are stable and specifiable. Pick retainer plus procurement fee if you are doing multi-room, multi-phase, or commercial work with clients who understand consulting billing.

The picks assume you are a solo or two-person studio doing 6-15 projects a year. If you are running a larger studio with junior designers billing time, the math changes. If you are doing single-room refreshes under $25K, cost-plus is often the only model that pencils, because the design fee needed under a flat-fee model looks disproportionate on a small project. See our related walkthrough on how to price a full living room refresh in 2026 for the small-project math specifically.

A few practical filters to run before you commit.

Cash timing. If you have less than three months of operating expenses in reserve, cost-plus is dangerous because you are floating vendor money. Flat fee and retainer both give you cleaner accrual.

Client sophistication. If your client is a tech operator, a finance client, or anyone who has bought design services before, they will price-check your product. The flat fee holds up in that conversation with zero defensiveness. Cost-plus requires you to be willing to justify the spread every time.

Scope stability. If you can specify a room in one meeting and the client will not add three more rooms mid-project, flat fee works. If scope grows organically (typical on custom homes and gut renovations), retainer works better because it flexes with time rather than reprising the fee conversation.

Vendor mix. If you spec heavily from vendors with published D2C pricing (RH, C&B, Serena & Lily, West Elm), cost-plus is structurally harder. If you spec mostly to-the-trade (Verellen, Lawson-Fenning, BDDW, 1stDibs, custom workrooms), cost-plus is more defensible because the client cannot easily cross-shop. Our companion piece on which vendors actually let solo designers use trade pricing covers the current landscape.

State law is quietly relevant here. A handful of states (California, New York, Florida, Texas, and a few others) treat design fees and product sales as distinct taxable categories, and cost-plus markups can trigger resale certificate requirements you might not have set up. Check with your accountant before you switch models. This is not optional and it is the kind of thing that surfaces two years later during an audit.

How do I explain my fee model to an interior design client without sounding defensive?

For interior designers, open the conversation before they ask. In the first paid consultation, before any spec work, walk them through your fee model in three sentences and hand them a one-page contract addendum showing exactly what each fee covers. If you wait until the client sees the invoice, you have already lost the frame.

Here is the script I use with a new client, adapted per model.

For cost-plus: "My fee model is cost-plus 33%. That means I buy every product at my trade cost, and you pay 33% over what I paid. That spread pays for the sourcing time, the vendor management, the freight coordination, and my time running punch at install. Most of my clients see about 15-20% off retail on the total project even after my markup, because trade discounts start deeper than the online sale price." Then hand them the addendum with a sample spec line.

For flat fee with net trade: "My fee is $15,000 flat for design of the living room. Product goes through you at exactly what I pay, and I will send you every vendor invoice. The reason this works is that I get paid for my time, not for how much you spend on the sofa. I have no incentive to spec up." Hand them the addendum showing a sample spec sheet with trade cost visible.

For retainer plus procurement: "My fee is $4,000 a month for the design work, and 12% on top of net trade for what it costs my studio to place and manage the orders. Trade cost is what I pay the vendor. The 12% covers my time placing POs, tracking freight, warehouse receiving, and delivery coordination. Product plus 12% is your out-of-pocket on product. Retainer is your out-of-pocket on design." Hand them the addendum with the operational task list.

The pattern across all three: name the model, name the number, name what the number pays for, hand them the paper. If any of those four steps is missing, you will be having the fee conversation on the client's timeline instead of yours. This is the single most useful discipline I have picked up in a decade of running design projects. The clients who become long-term clients are the ones who felt the fee model was already handled by the time we got to spec.

What do I do when an interior design client finds my trade cost online and asks about the markup?

When an interior design client finds your trade cost online, do not deflect. Confirm the number, restate the fee model, and reframe the value. The moment you sound defensive is the moment the client stops trusting the process. Most designers lose this conversation not because their fee model is wrong but because they treat the question as an accusation.

The specific language that works. "Yes, my trade cost on that sofa is $6,840. The client price is $9,100 because my contract with you is cost-plus 33%. What that $2,260 pays for on that specific sofa is: the vendor call to hold inventory, the freight quote and consolidation, the white-glove delivery scheduling, the receiving inspection at the warehouse, and the on-site placement day. If you would prefer to buy the sofa directly at trade and handle those steps yourself, we can amend the contract to a flat-fee model going forward and I will pass net trade on remaining items. I would rather have that conversation now than have it be weird later."

Three things that script does. It confirms the number instead of hiding it. It maps the spread to concrete work, not vague "expertise." It offers a real alternative. Most clients, when offered the alternative, decline. They realize the operational work is not free and they do not want to do it. The 20% or so who accept the swap were going to have that fight eventually regardless of the model. Better to have it in month one.

If the client is finding your trade cost through a designer directory or a leaked B2B portal, that is a separate problem. Some vendors (notably certain 1stDibs sellers and a handful of workrooms) publish trade pricing in ways that end up indexed by Google. Know which of your vendors do this and either avoid them for cost-plus projects or move those specific line items to a flat-fee arrangement inside the same contract.

There is a harder version of this conversation, which is when the client finds a similar item on Wayfair or Article for half the price. This is not the same conversation. Trade product from a workroom is genuinely different from mass-produced product with the same silhouette. Coil-spring seat vs. sinuous webbing, kiln-dried hardwood vs. engineered plywood, eight-way hand-tied vs. drop-in cushions. If you cannot walk a client through the construction difference in 90 seconds, you owe it to yourself to learn. The Furniture Society and AHFA both publish construction-quality primers that are worth an hour of your time.

If the client persists after that walkthrough, the honest answer is that they are not your client for this project. Refer them to a Havenly-style e-design service and part on good terms. There is no fee model that survives a client who fundamentally does not value the difference between a $2,200 sofa and a $6,800 sofa. That is a positioning mismatch, not a pricing problem.

The last piece of infrastructure this all depends on is having your trade accounts set up correctly in the first place, with vendor terms that match how you actually invoice. Our prerequisite guide on how to set up trade accounts as a solo interior designer covers the account-opening playbook that makes any of these three fee models operational.

Pick the model that matches how you actually work. Document it in the contract. Walk the client through it before they ask. Every fee-model debate that goes sideways at month four is a documentation failure at month one.