Build an Invoicing App for Your Web Design Agency

Web design agency invoicing has two halves: staged invoices for builds, and recurring invoices for maintenance and hosting plans that must never be forgotten. Describe your payment stages and plans, and Mythex builds an app that raises both on schedule, bills change requests and shows what is overdue.

Who it's for

Agencies that discover in March that a dozen care plans were never invoiced in January, and that start design work before the deposit has cleared.

What you can build

Deposit, design sign-off and launch invoices per project
Monthly or yearly care plan invoices on each renewal date
Change request invoices for work outside scope
Domain, hosting and licence costs passed through
A renewals-due list for the next 60 days
PDF invoices with your agency branding

Plans that invoice themselves

Late maintenance invoices are rarely refused; they are forgotten, and the lost months never get billed. Give each plan a price, a cycle and a start date, and the app raises the invoice on every renewal date without anyone remembering. A list of renewals due in the next sixty days sits beside overdue invoices so nothing lapses quietly.

Plan price, cycle and start date
Invoices generated on renewal
Price changes applied from a set date

Stage builds and invoice the deposit first

Tie each project to payment stages and what triggers them: deposit on signing, a second payment at design sign-off, the balance at launch. The deposit invoice goes out before design starts, and the next stage is raised when you mark the milestone done, so the cash keeps pace with the work.

Change requests and scope

When a client asks for something outside the agreed scope, log it as a change request with an estimate they approve. Approved requests become invoice lines automatically. It keeps the conversation about scope factual and stops small extras going unpaid.

Pass-through costs

Domains, premium plugins, fonts and third-party subscriptions bought for a client can be invoiced at cost or with your markup, shown as separate lines. Record their renewal dates too, since a lapsed domain is a much bigger problem than a late invoice.

A prompt to start from

Build an invoicing app for my web design agency. Projects have staged payments (40% deposit, 30% at design sign-off, 30% at launch) raised when I mark each milestone. Care plans have a monthly or yearly price and renewal date and invoice automatically. Approved change requests become invoice lines, domains and licences pass through with an optional markup, and a dashboard shows renewals due in 60 days and overdue invoices.

Questions

Can maintenance plans invoice automatically each month?

Yes. Each plan has a cycle and renewal date, and the invoice is generated on schedule. Card payments go through a payment provider on your own account.

Can I invoice in project stages?

Yes. Define the stages and percentages; each invoice is raised when you mark the milestone complete.

Can it produce branded PDF invoices?

Yes. Ask for a printable layout with your agency's logo, details and numbering.

Does it handle tax?

Say which tax applies and at what rate and it is calculated per line. Check the treatment of digital services where your clients are with your accountant.

Is it free?

The Free plan needs no credit card and gives daily credits, enough to build and publish a first version. Pro is $25/month.

Templates to start from

Agency Portfolio Template — Pricing calculator with booking
Fintech Payments Site Template — Tiered pricing, blog, animations
AI Trip Planner Template — Chat itineraries with billing-ready UI
Invoice Generator Template — Canvas invoicing with PDF export
Cloud Storage SaaS Template — Marketing site, billing UI, and 2FA
Agency Client Portal Template — PIN-protected views on a Kanban board
Subscription News Site Template — Paywall-ready editorial grid
Grid Agency Portfolio Template — Auto-rotating carousel and case studies