How to write an interior design invoice

How you charge decides how the invoice looks

Interior design has more ways of charging than almost any other trade, and a single project can use three of them. The ASID Minnesota chapter lists the main ones, and notes that combinations are common, such as an hourly or fixed rate for design time with cost-plus on the products you buy.

Each method produces a different block on the page. The mistake is letting them run together. Keep fee lines, product lines and pass-through costs in separate groups, so a client reading the invoice can see at a glance which money paid for your thinking and which paid for a sofa.

Interior design invoice example, filled in

The second of three phase invoices on a living and dining room: a fixed-fee installment, two cost-plus purchases, freight passed through at cost, and the retainer applied. Amounts are samples.

The lines come to $6,366. Tax of $300.48 is on furnishings and markup only ($3,756), the total is $6,666.48, and after the $1,500 retainer $5,166.48 is due. Each purchase carries its PO number, so the client can match it to the vendor invoice.

The retainer is a credit, and it should stay visible

ASID describes a retainer as money the client pays to the designer that is applied to the balance due. On paper that means it never disappears. Show it as a credit line on every invoice until it is used up, with the amount remaining, and say in the agreement whether it is applied to the first invoice, spread across the project or held to the end. All three exist, and a client who was not told will assume the most generous one.

Purchase orders: one item, one deposit, one line

Procurement is where design invoices get messy, and purchase orders are the cure. Give every item you order its own PO number and carry that number onto the client invoice. Read each vendor's return terms before you order, and if a piece cannot be sent back once it is ordered, take the client's money before you commit yours.

A procurement deposit invoice for one purchase order. The percentage is a sample; set yours in the design agreement.

Two invoices per item sounds like more paperwork, but it is less arguing. The deposit invoice names the item, the vendor lead time and the PO number. The balance invoice shows the deposit as a credit and asks for the rest on delivery, after the inspection the agreement promised. The mess to avoid is a client paying a showroom directly while you also invoice a deposit for the same piece; decide per item who pays the vendor, and write it on the PO.

Sales tax: fees, furnishings, installation and fabrication

Tax is the part of a design invoice that varies most by state, and it is worth settling before the first purchase. California is unusually clear. Its CDTFA Publication 35 for interior designers says professional services not directly related to the sale of merchandise are not taxable, but charges for services that are part of a taxable sale of merchandise are taxable. It says installation labor is not taxable, while fabrication labor is, whether or not you supply the materials. And its resale certificate section says that to buy goods for resale without paying tax you must give the seller a properly completed resale certificate, and that you should not issue one for items you will use yourself.

Washington draws the lines differently. The Washington Department of Revenue guide says income from design and consulting services falls under its business and occupation tax, and that designers must pay sales tax on their own purchases of samples, swatches, decorator magazines and books. Two states, two structures. Ask your own revenue department how design fees, markup, freight, installation and fabrication are treated, keep copies of every resale certificate you issue, and build the tax line from that answer. The example above taxes furnishings and markup only, which matches some states and not others.

Expenses, freight and the fee that seems to grow

ASID's definition of a fixed fee excludes expenses, so samples, prints, courier charges and travel go in their own block with receipts and a stated rule on markup, if you add any. Freight, receiving and warehouse charges are pass-throughs as well; label them "at cost" when they are. A client who sees a fixed fee line and a separate reimbursables block sees a bill that matches the agreement. A client who sees one bigger number sees a fee that crept.

When the scope changes, such as a new room or a reselection after an order, issue a written change before the work and give it its own line on the next invoice. Design projects run for months, and memories of what was agreed fade faster than invoices do.

Before the invoice goes out

• Fee lines, product lines and pass-throughs in separate groups.
• A PO number and vendor invoice behind every cost-plus item.
• The markup percentage written out, matching the agreement.
• Retainer and deposits as credits, with any remaining balance.
• A tax base stated, built from your state's rules, not a neighbor's.
• Delivery and inspection terms for anything still to arrive.

Interior design invoice questions

Free interior design invoice template

There is no interior design preset in the generator. Open Other / general business and type the lines, or start from Architect if your fees are phased. To work in a spreadsheet, download the blank invoice as Word, Excel or PDF, and use the purchase order template for the vendor side of each item.

Design and project trades

Tools for design studios

Fees, procurement and retainers.