Interior design invoicing software that matches the agreement
Interior design invoicing software raises GST invoices at each agreed milestone, tracks part-payments and sends reminders, so money arrives on time. In the D&B Operating System, invoices follow the signed agreement, accounts see money due, received and overdue, and reports show profit per project. Exports go to your accountant. BRANDSWOT Consultancy built it for interior and design-and-build firms.
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Where interior firms lose money
The work gets done, but the bill goes out late. The milestone was reached two weeks ago, yet nobody told accounts. A client pays part of an invoice by UPI and part by cheque, and one of them never gets recorded.
Extra work is the other leak. The client asks for a TV unit on site, the carpenter builds it, and the cost appears only on the final bill. The client disputes it, and the firm absorbs the loss. Project profit is known only at the end, when it is too late to fix.
How the interior design invoicing software works
- The approved quotation becomes the agreement, with scope, milestones and payment schedule.
- When a milestone is reached, accounts raise a milestone invoice with GST.
- Payments are recorded as they arrive, including part-payments.
- Payment reminders go out for amounts that are due or overdue.
- Receipts are issued for every payment received.
- Extra work is logged as a change request before it starts, then billed.
- Vendor bills and expenses are recorded against the project.
- Reports show project profitability, and exports go to your accountant.
Who uses it
- Accounts: quotes from rate cards, milestone invoices with GST, reminders, receipts, vendor bills, expenses and exports.
- Owner: money due, received and overdue on one dashboard, plus profit per project.
- Project manager: logs change requests so extra work is approved and billable.
- Site supervisor: confirms on-site progress that triggers the next milestone.
What the client sees
The client gets invoices that match the agreement they signed, with the same milestones and amounts. Each payment comes with a receipt. Extra work arrives as a change request to approve before it is built, not as a surprise on the final bill. Every document carries your firm's brand.
GST, works contracts and TDS: what to check
GST on most professional and design services in India is 18%. Show the taxable value, GST and total separately on every invoice.
Turnkey jobs that include material and labour for a home or office can be works contracts under GST, which have their own rules on rate and input tax credit. Some business clients must also deduct TDS from payments to contractors or professionals. The right treatment depends on the contract, so confirm it with your CA and keep TDS certificates with each invoice record.
This is general information, not tax advice. Rules change; check current GST and Income-tax guidance with a qualified professional.
Payment terms that protect the firm
Write payment terms into the agreement, not just the quote. Link each payment to a visible stage, such as booking, design sign-off, material order, installation and handover. Clients pay faster when they can see what they are paying for. The interior payment schedule template in our library gives you a starting format.
Related client work
D&B Operating SystemMore questions
What are standard payment terms for interior projects in India?
There is no fixed standard. Most firms take a booking advance, then stage payments linked to design sign-off, material order or production, installation and handover. Some ask for the full material cost upfront for custom items. Write the stages, amounts and due days into the agreement, and say what happens if a payment is late.
How do I send payment reminders professionally?
Send the invoice on the day the milestone is reached, then a polite reminder a few days before the due date. Keep it short: amount, invoice number, due date and how to pay. After the due date, remind on fixed dates and call if needed. Stay factual and calm. The D&B Operating System sends reminders for due and overdue amounts.
Is works contract GST applicable to interior projects?
It can be. Under GST, a works contract covers building, fitting out, renovating or repairing immovable property where goods are transferred as part of the job. Many turnkey interior jobs fit this. A works contract is treated as a supply of services, and input tax credit rules differ. Confirm the rate and treatment for each contract with your CA.
Do interior designers need to deduct TDS?
Sometimes. If your firm is liable to deduct, contract payments to subcontractors may need TDS under the contractor-payment provisions. Professional and technical fees have their own TDS provisions, and the Income-tax Act, 2025 renumbered these sections, so check the current section with your CA. Whether you must deduct depends on your entity type, turnover and payment size. Check current thresholds and rates with your CA. Your own business clients may also deduct TDS from your invoices.
What happens if a client cancels an interior project midway?
It depends on your agreement. A clear cancellation clause says the client pays for work done, materials ordered and custom items already made, plus any agreed fee. Without one, disputes follow. Record progress with dated photos and keep change requests approved. In the D&B Operating System, milestones, change requests and site updates give a clear record of what was delivered.
How do I track project expenses against budget?
Set the budget from the approved quote and its BOQ cost lines. Record every vendor bill, labour payment and site expense against the project as it happens. Compare spend with the budget at each milestone, not at the end. For expense tracking on interior projects, the D&B Operating System records vendor bills and expenses per project and reports profit per project.
Questions people ask
What is milestone billing in interior projects?
Milestone billing means raising an invoice when a defined stage is reached, such as design sign-off, material order, installation or handover. Each milestone and amount is fixed in the agreement. In D&B Operating System, milestone invoices with GST follow the signed agreement, so the client is billed exactly what was agreed.
What is the GST rate on interior design services in India?
GST on most professional and design services in India is 18%. Turnkey jobs that combine material and labour may be treated as works contracts, which have their own rules. Confirm the correct treatment for each contract with your CA before you invoice. D&B Operating System raises milestone invoices with GST shown clearly.
How much advance should an interior designer take?
Take enough advance to cover design time and the first material orders, so the firm never funds the client's project. The amount varies by firm and scope. Write the advance and every later stage into the agreement, and link each payment to a visible milestone the client can check.
How do I stop clients delaying payments?
Invoice the day a milestone is reached, send polite reminders on fixed dates, and link the next stage of work to the last payment. In D&B Operating System, accounts see what is due and overdue, payment reminders go out on time, and receipts confirm every payment.
How do I handle change orders and extra costs?
Log every extra as a change request with scope and price before work starts, and get the client's approval in writing. Then bill it at the next milestone. D&B Operating System records change requests against the agreement, so extras never appear as a surprise on the final bill.
How do I calculate profit on an interior project?
Profit is what the client paid minus every cost: materials, vendor bills, labour, site expenses and design time. Track costs against each project as they happen, not at the end. D&B Operating System records vendor bills and expenses per project and reports project profitability while work is still running.
Is there free billing software for interior designers?
Free GST billing apps exist and work for simple invoices. They usually do not link the invoice to the quote, agreement, milestones and project costs. D&B Operating System does not publish a free plan; pricing is on request after a demo. Check each vendor's current features before choosing.