Build an Invoicing App for Your Virtual Assistant Business

Virtual assistant invoicing comes down to two numbers: the package you bill at the start of the month and the extra hours you bill at the end. Describe your packages and rates, and Mythex builds an app that logs time against tasks, generates both invoices and shows each client where the hours went.

Who it's for

VAs and small VA teams who log hours in a spreadsheet, invoice from memory at month end, and have had a client question a bill because they could not see the hours building up.

What you can build

Monthly package invoices issued on the 1st
Overage hours at each client's rate at month end
A time breakdown by task on every invoice
Reimbursable expenses as separate lines
Rollover or expiry of unused hours, by your rule
Paid, due and overdue status per client

Log time where the task is

Invoices go wrong when time is logged in a different place from the work. Give each task a timer and a manual entry option, tied to the client and the package month. At month end the hours are already grouped by task, and the invoice reads 'calendar clean-up 1.5h, travel booking 2h' rather than a single total the client has to trust.

Timer and manual entry per task
Task types for reporting
Notes on what was done

Package in advance, overage after

Billing the package upfront commits the client and covers your month. Overage is calculated from logged hours beyond the package at that client's rate and invoiced at the end. Decide whether unused hours roll over for a month or expire, put it in your terms, and tell Mythex the rule so it is applied every time.

Expenses and software bought for clients

When you pay for a tool, a domain or a booking on a client's behalf, record it with the receipt and it appears as a separate reimbursable line. Keeping it apart from hours makes both easier to check.

Get paid without chasing

Connect a payment provider on your own business account and add a pay link to each invoice, or a saved card for monthly packages if your provider supports it. Clients in other countries may need a different currency; say which ones you bill in.

A prompt to start from

Build an invoicing app for my virtual assistant business. Each client has a monthly package of hours, a package price and an overage rate. I log time on tasks with a timer or manual entry. On the 1st, generate the package invoice; at month end, generate an overage invoice for hours beyond the package with a breakdown by task. Unused hours roll over for one month only. Add reimbursable expenses with receipts and PDF invoices with my logo.

Questions

Can it bill overage hours automatically?

Yes. Hours beyond the package are calculated from your time logs and added at each client's overage rate on the month-end invoice.

Can clients see the hours before the invoice?

Yes, if you add a client portal in the same project. It shows hours used against the package as you log them.

Can I invoice in other currencies?

Yes. Set a currency per client and say how you want amounts shown.

Can it produce PDF invoices?

Yes. Ask for a printable layout with your business details, logo and numbering.

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

Fintech Payments Site Template — Tiered pricing, blog, animations
Meeting Booker Template — Timezone-aware slots, one shared link
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
Freelance Invoicing Template — Saved clients with revenue stats
Internal Request Queue Template — Multi-stage approvals with SLA timers
Product Roadmap Template — Canvas timeline and sortable list view