How to Invoice as a Virtual Assistant: Retainers and Hours

A virtual assistant invoice has three jobs: request payment, prove the work happened, and remind the client of the rules you agreed on. Clients never see you work, so a single "VA services: $816" line invites questions. A short breakdown of hours by task, plus clear overage and rollover lines, answers them before they are asked.

This guide covers how to structure retainer and hourly invoices, a complete worked example, the payment terms that suit VA work, and the tax paperwork US and UK clients expect. For setting your rates in the first place, see how to price virtual assistant services.

What should a virtual assistant invoice include?

Include the standard invoice details, then add the VA-specific lines that explain the total. In the UK, every invoice must show a unique identification number, your business name, address and contact details, the customer's name and address, a clear description of what you are charging for, the supply date, the invoice date, the amounts charged, VAT if applicable, and the total owed; sole traders trading under a business name must also show their own name and an address where legal documents can be delivered (GOV.UK: Invoices, what they must include, accessed October 2026). US clients expect the same basics even though no single federal list applies.

On top of that, a VA invoice should show:

• The service period for each line ("1-31 May" for the retainer, "April" for overage).
• Hours by task category for the period, even on a flat retainer.
• Overage as its own line with the hours and rate.
• Reimbursable costs you paid on the client's behalf, at cost, with the receipt attached.
• Payment terms and methods, including bank details or a payment link and the currency.

The virtual assistant invoice template shows one layout, and what to include on an invoice has the general checklist.

Worked example: a retainer invoice with overage

Hypothetical example. A VA works for a coaching business on a 20-hour monthly retainer at $35 an hour, paid in advance. Hours beyond the retainer are billed at $40, and unused hours do not roll over. In April the VA worked 22.5 hours. The invoice dated 1 May, due 8 May, looks like this:

Below the lines, a short hours summary for April (not priced, because the retainer already covers it):

Two lines of notes finish the invoice: "Retainer hours do not roll over. Additional hours are billed at $40 in the following month." The client can check every number without asking.

How should overage and rollover work?

Decide both rules before the first invoice and repeat them on every invoice; most VA billing disputes come from one of the two being vague.

Overage. Set a rate (many VAs charge slightly more than the retainer rate for hours above the block) and a notice rule, for example "I'll tell you when you reach 18 of 20 hours." Bill overage in arrears on the next invoice, as in the example.

Rollover. Three common policies:

Capped rollover is a fair middle ground for clients with uneven months. Whatever you choose, show the balance on the invoice: "Rollover: 4 hours carried from March, expire 30 April."

When should you send VA invoices, and on what terms?

Send retainer invoices at the start of the period and hourly invoices at least every two weeks. Short cycles keep each invoice small enough to approve without a conversation.

Hourly example. A VA billing $38 an hour sends an invoice every second Friday. For 14.25 hours over two weeks, the invoice is 14.25 × $38 = $541.50, with dates and tasks listed per day or per category.

Terms that suit VA work:

• Retainers: due before the period starts or within 7 days of the invoice. Work paused if unpaid after a stated number of days.
• Hourly: Net 7 for new clients; Net 14 once a client has paid on time for a few months.
• Projects: a deposit (often 50%) before starting, the balance on delivery.
• International clients: state the currency, who pays transfer fees, and the payment methods you accept.

If late payment becomes a pattern, the late payment guide covers reminders and when to pause work, and invoicing retainer agreements covers how to write the retainer terms themselves.

Which tax forms and rules apply to VA invoices?

This depends on where you and your clients are. The points below are general information for the US and UK, last reviewed October 2026; check your own position with your tax authority or an accountant.

US clients and US-based VAs. Clients usually ask for a Form W-9 before the first payment. For payments made in 2026, a client generally files Form 1099-NEC when it pays an independent contractor $2,000 or more for services in the year; for payments made before 2026 the threshold was $600 (IRS: Form 1099-NEC and independent contractors). Payments made by credit card or through a third-party payment network are reported on Form 1099-K by the payment company, not on a 1099-NEC (IRS: Instructions for Forms 1099-MISC and 1099-NEC). The income is taxable whether or not a form is issued, so keep your own invoice records.

VAs outside the US with US clients. Clients typically ask for Form W-8BEN instead of a W-9 to document that you are a foreign person (IRS: About Form W-8 BEN).

UK-based VAs. You must register for VAT if your taxable turnover for the last 12 months goes over £90,000 (GOV.UK: When to register for VAT). Below that, your invoices show no VAT. Once registered, invoices to VAT-registered clients must be full VAT invoices.

Sales tax in the US depends on whether your state taxes the specific service you provide. Check your state's guidance before adding tax to an invoice.

What are the most common VA invoicing mistakes?

• One lump-sum line. "VA services, May: $700" with no hours breakdown is the invoice most likely to be questioned.
• Rules only in the contract. Clients forget the rollover and overage terms; put them on the invoice too.
• Absorbing tool costs. If you buy software for a client's account, bill it at cost as a reimbursable line with the receipt, or ask the client to pay the vendor directly.
• Logging hours at month end. Reconstructed timesheets undercount short tasks. Log daily, in categories that match your invoice.
• Sharing one retainer between two people. If a second person at the client's business starts sending tasks, agree whether their hours come out of the same block before the invoice arrives.
• No pause clause. Without one, you keep working on a retainer that has not been paid.

Can AI make a VA invoice for you?

Yes. Several invoicing tools can draft an invoice from a description, and InvoiceQuickly is built around that. You type or say something like "Invoice Brightpath Coaching $700 for the May VA retainer, 20 hours, plus 2.5 April overage hours at $40 and $16 reimbursable scheduling software", and it drafts the client, line items, rates and terms into an editable invoice that you review before saving. It does not send anything on its own.

What it covers for a VA:

• Free: 5 invoices, 5 clients and 3 AI drafts in total, with PDF download and payment recording. Enough to try it on one client.
• Pro ($9/month): unlimited invoices and AI drafts, email delivery, a payment link from your own Stripe or PayPal account, scheduled reminders before and after the due date, recurring invoices for retainers (created as a draft for review or sent automatically), a client portal and CSV export.
• Currencies: the editor offers USD, EUR, GBP, CAD, AUD, INR and PKR, without automatic conversion.

What it does not do: there is no retainer hour-cap or rollover counter, so check hours against the block yourself. Pro does track time (a timer or manual entries), or you can log hours in your usual tool and type the totals; a recurring schedule creates a single retainer line, so add overage and reimbursements to the draft each month before sending; and your tax ID is copied to new invoice PDFs; check the saved IDs and PDF before sending. See the pricing page for plan details.

Frequently asked questions

Should a virtual assistant invoice before or after the work?

Retainers are usually invoiced before the month starts, because the client is reserving your time. Hourly work is invoiced after it is done, weekly or every two weeks. Projects often take a deposit up front and the balance on delivery.

How do I show hours on a retainer invoice?

Bill the retainer as one line, then add an unpriced summary of hours by task category for the previous month, with the total compared with the retainer. Bill any hours above the retainer as a separate overage line.

How do I write up a simple invoice as a VA?

List your name and business details, the client's details, a unique invoice number, the invoice date, the service period, one line per service with hours and rate, any reimbursable costs, the total, the due date and how to pay. Use the same format every month so clients can approve it quickly.

Do I need to send a W-9 to my VA clients?

US clients usually ask US-based contractors for a W-9 so they can file Form 1099-NEC if required. For payments made in 2026, that filing generally applies when they pay you $2,000 or more in the year. VAs outside the US usually provide a W-8BEN instead.

Should I charge clients for the software I use for them?

Tools you use for all clients are part of your overhead and belong in your rate. Tools bought for one client's account can be billed at cost as a reimbursable line with the receipt attached, or paid by the client directly.

Can I bill for time spent on emails and calls with the client?

Yes, if your agreement says so. Most VAs count client communication as billable time and show it as its own category, such as "client calls and updates", so the client sees it was included.