How events and design professionals invoice
Projects in events, architecture, and interior design share a common challenge: long timelines, multiple suppliers, and costs that evolve as the project progresses. Your invoicing needs to match that complexity without burdening the client with confusion.
Phased billing is the standard approach for architects and interior designers. Each project phase — briefing, concept, detailed design, construction documentation, site visits — is a defined scope of work that justifies its own invoice. Billing by phase aligns payment with approved progress and protects you if a client cancels mid-project.
Materials and supplier procurement are typically billed at cost plus a markup — 10–20% is common — to cover your coordination time and procurement risk. Show this clearly on the invoice: either as a line item per item or as a combined materials total with your markup percentage stated. Agree on your markup policy in the client agreement before any procurement begins.
Event planners often use a three-invoice structure: deposit on engagement, progress payment at a defined production milestone, and final balance after the event with any overages. Change orders — additions to the original brief — should be invoiced separately or flagged as a distinct line item so the client can reconcile against the original estimate.
Events & design invoice checklist
- Phase or milestone name — clearly identify which phase or deliverable the invoice covers
- Professional fee — your time and expertise for that phase, at agreed rate or fixed fee
- Materials / supplier costs — at cost or cost-plus-markup, with markup rate stated
- Change orders — any scope additions billed separately with a brief description
- Deposit or progress payment reference — deduct previously paid deposits on the final invoice
Tips for events, architecture & interior design professionals
Structure your deposit schedule upfront
Agree on a payment schedule before work begins — deposit, progress payment(s), and final balance. Put it in writing in your agreement. When payment milestones are pre-agreed, invoices become expected rather than a surprise, and collections are faster as a result.
Be transparent about materials markup
Clients are rarely surprised by a markup when they know about it in advance. State your procurement markup rate in your initial proposal — 'All materials are sourced at cost plus 15%' — and reflect it clearly on invoices. Transparency builds trust and prevents disputes at the billing stage.
Document every change order in writing
Scope changes are inevitable in long projects. Every time a client requests something outside the original brief, send a brief written change order before doing the work. Reference the change order number on your invoice so the client can trace every line item back to an approved change.
Frequently asked questions
How do I invoice for architect fees by project phase?
Architectural fees are typically billed as a percentage of construction cost or as a fixed fee split across defined phases: briefing and feasibility, concept design, detailed design, planning application, construction documentation, and site inspection. Invoice each phase on completion, naming it clearly — 'Phase 3: Detailed design — 20% of agreed fee'. This ties payment to client-approved milestones and avoids disputes over progress.
Should I mark up materials on my invoice?
Yes, a materials markup is standard practice for interior designers, event planners, and architects who source and procure on behalf of clients. A 10–20% markup on supplier costs covers your time, coordination effort, and the risk of managing procurement. State your markup policy in your client agreement upfront and show materials at the marked-up price on the invoice, or as cost-plus-markup if the client has asked for transparency.
How do I handle event planning deposit invoices?
Send a deposit invoice — typically 30–50% of the estimated total — at the time of engagement to secure the date and cover initial planning costs. Use a second invoice for a progress payment midway through production, and a final invoice after the event to settle the balance plus any overage costs. Label each invoice clearly: 'Deposit invoice', 'Progress payment', 'Final balance'. Keep a detailed line-item breakdown on the final invoice so the client can reconcile against the original estimate.