The virtual assistant's guide to contracts and invoicing (UK)

Virtual assistant work runs on two things: trust and access. A client hands you the keys to their inbox, their calendar, sometimes their invoicing and their passwords — and expects it all handled quietly and well. That trust is the whole job, and it's exactly why the business side deserves the same care as the work itself. A clear agreement and clean, regular invoicing are what let a VA business grow calmly instead of lurching from one loosely-defined arrangement to the next.

This guide covers both: the contract terms that are worth pinning down for VA work specifically, how to price and invoice retainers and hourly work, and how to make sure you're paid on time.

A quick note first: TrustSolo isn't a law firm or an accountancy, and nothing here is legal or financial advice. Its contract templates are customisable starting points, not solicitor-reviewed documents — for a high-value or unusual engagement, a professional opinion is worth the money. What follows is a plain-English guide to the things worth thinking about.

Why a written agreement matters more for a VA

Two features of VA work make a written agreement more valuable than it might be in some other freelance fields.

The first is that the role is broad and it drifts. You're taken on for "inbox and diary," and three months later you're also booking travel, chasing invoices and moderating a community. Each addition is small and reasonable in isolation — but with no agreed scope, they accumulate into a full-time job paid at part-time rates. Scope creep is the defining risk of VA work, and the simplest defence against it is a written line about what's included and what's charged separately.

The second is the access. You'll routinely hold credentials to systems that matter — email, banking-adjacent tools, client data, sometimes their customers' data. That raises the stakes on confidentiality and on what happens to your access when the work ends. None of this means expecting the worst of a client; it means both of you sharing the same understanding, in writing, before it's ever tested.

This is worth doing even for a friendly, open-ended retainer. Especially then, in fact — the arrangements that run for years on goodwill are the ones where nobody can quite remember what was agreed.

The terms worth nailing down

You don't need a long document. A clean agreement covering the following handles the great majority of what actually goes wrong in VA engagements:

• Scope of tasks — what you're doing, and just as importantly what falls outside it and is quoted separately. This is your anti-scope-creep clause.
• Hours and availability — whether it's a set monthly block of hours or ad-hoc, your working pattern, and a sensible note that you may vary availability for holidays or illness with reasonable notice.
• System access and security — that you'll use credentials only for the agreed work, won't share them, and will cease all access on termination. Crucially, that the client is responsible for revoking your access when the engagement ends. This is the most commonly overlooked clause in VA agreements — clients routinely forget to remove access after you've moved on, which is a risk to both of you.
• Confidentiality — VAs handle unusually sensitive material: passwords, financials, client lists, personal data. A confidentiality clause that reflects that elevated trust, and that survives the end of the engagement, is standard for good reason.
• Notice period — how much notice either side gives to end an ongoing arrangement. Thirty days is a common, sensible default for a retainer, so a client can't simply vanish mid-month and leave you with a hole in your schedule.
• Who pays for tools — if the work needs paid software or subscriptions, say up front whether the client covers them.

TrustSolo's virtual assistant contract template is built around exactly these — agreed tasks, system access, confidentiality and notice periods — as a customisable starting point you adjust to the engagement. You can see how it works under contracts.

Retainer or hourly? Two ways to charge

Most VA work is priced one of two ways, and the choice shapes how you invoice.

A monthly retainer is a set block of hours or a defined scope for a fixed monthly fee. It's predictable for both sides — steady income for you, a known cost for the client — and it's the model most established VAs move towards. The things to settle are what happens to unused hours (do they roll over, or lapse at month end?) and how work beyond the block is charged.

Hourly or ad-hoc billing suits newer relationships and irregular work. You track your time and bill for what you actually do. It's flexible and low-commitment, but your income moves around with the client's needs, which is why many VAs use it to start and shift to a retainer once the relationship settles.

Whichever you use, price it properly. As a VA your rate has to cover the unbillable hours — admin, client-hunting, your own tools — not just the time at the keyboard. For a sense of the going rate, see what UK virtual assistants charge; our free rate calculator then works backwards from the income you need to a sustainable rate, and needs no sign-up.

Invoicing as a VA

The cadence usually follows the pricing model. A retainer is typically invoiced in advance — the month's fee at the start of the month, so you're paid for the capacity you're holding open. Hourly work is usually invoiced in arrears, at the end of the month or the piece of work, against a simple record of the time you spent. Keeping that time record as you go, rather than reconstructing it later, is the small habit that makes hourly invoicing painless and keeps queries easy to answer.

The invoice itself follows the same rules as any freelance invoice — a unique number, your details and the client's, a clear description, the amount and a due date. Our companion guide, how to invoice as a freelancer in the UK, walks through exactly what every invoice must include and how to set payment terms.

For a new client, asking for the first month up front — or a deposit before you begin — is entirely normal, and a reasonable filter for how serious and reliable a new client is likely to be.

Getting paid on time

Most late payment is disorganisation, not bad faith, and a short, factual reminder settles the great majority of it. But if a payment genuinely drags on and your client is a business, you have the same statutory protections as any freelancer: the right to charge interest at 8% plus the Bank of England base rate on the overdue amount, plus a fixed recovery cost of £40, £70 or £100 depending on the size of the debt. Our guide to late-paying clients walks through the whole escalation ladder.

You'll rarely need to reach for any of that. The stronger position, as ever, is a clear invoice sent on a predictable schedule with a due date on it — and, for retainers, invoicing in advance so the money arrives before the work does.

How TrustSolo helps VAs

TrustSolo is built to take the admin out of exactly this loop. The virtual assistant contract template gives you a customisable starting point covering tasks, access, confidentiality and notice; the invoicing handles your retainer or hourly billing with a payment link attached; and a running estimate of your Income Tax and Class 4 National Insurance keeps your numbers in view as you go. It's there to make the business side quiet and predictable, so your attention stays on the client work — with the commercial decisions, as they should be, left to you.

The tailored view for virtual assistants lives at TrustSolo for VAs.

Get the agreement and the invoicing right early and the rest of a VA business is mostly just doing good work. When you'd like the paperwork to look after itself, you can start free — no card required.