If you run a UK agency, VAT is one of the first tax obligations you'll hit as you grow. The current registration threshold is £90,000 in taxable turnover over a rolling 12-month period [1]. Once you cross that line, you must register and start charging VAT. But many agency founders choose to register voluntarily before that point, especially if they work with larger clients who are VAT-registered themselves.
This article explains how to calculate VAT for your agency. We'll cover the standard calculation, the flat rate scheme, and how to handle common agency scenarios like retainers, project fees, and expenses. We'll use real numbers throughout.
When Do You Need to Register for VAT?
You must register for VAT if your total VAT-taxable turnover exceeds £90,000 in any rolling 12-month period [1]. This is not a fixed tax year check. HMRC looks at your cumulative turnover over the last 12 months. If you hit £90,000 in March, you register in March. If you hit it in November, you register in November.
You can also register voluntarily if your turnover is below £90,000 [1]. This is common for agencies because:
- It lets you reclaim VAT on your own costs (software, rent, equipment).
- It makes you look more established to larger clients.
- It avoids a sudden registration spike when you cross the threshold mid-year.
Once registered, you must include VAT in the price of all goods and services at the correct rate [1]. For most agency services, that means the standard 20% rate. You must also submit a VAT return to HMRC, usually every three months, reporting the VAT you charged customers and the VAT you paid to other businesses [1].
The Basic VAT Calculation: Standard Rate (20%)
The standard rate of VAT in the UK is 20%. Most agency services fall under this rate. There are two directions you need to calculate: adding VAT to a price, and removing VAT from a price.
Adding VAT to a Price (Excluding VAT to Including VAT)
To work out a price that includes the standard rate of VAT, multiply the price excluding VAT by 1.2 [2].
Example: You sell a website build for £5,000 excluding VAT. The price including VAT is £5,000 x 1.2 = £6,000. The VAT element is £1,000.
If you quote a client £5,000 for a project, and you are VAT-registered, your invoice must show the VAT separately. The total the client pays is £6,000. If your client is also VAT-registered, they reclaim that £1,000 on their own VAT return. It costs them nothing net. If your client is not VAT-registered (a small business or a consumer), they pay the full £6,000.
Removing VAT from a Price (Including VAT to Excluding VAT)
To work out a price that excludes the standard rate of VAT, divide the price including VAT by 1.2 [2].
Example: You buy a new laptop for your agency. The total price including 20% VAT is £1,200. The price excluding VAT is £1,200 ÷ 1.2 = £1,000. The VAT you can reclaim is the difference: £200 [2].
This calculation is essential when you are reviewing your costs. If you pay £600 a month for software including VAT, the net cost is £500 and the reclaimable VAT is £100.
The Flat Rate Scheme: A Simpler Option for Small Agencies
The Flat Rate Scheme (FRS) is an alternative to standard VAT accounting. It is designed to simplify VAT for small businesses. Instead of calculating the difference between output VAT (what you charge) and input VAT (what you pay), you apply a fixed percentage to your total turnover (including VAT) and pay that to HMRC. You keep the difference.
For agencies, the flat rate percentage depends on your sector. A management consultancy pays 14.5%. A marketing agency pays 12.5%. A creative agency pays 13.5%. You can check the exact rate for your sector on the gov.uk website.
Example: Your agency bills £60,000 in a quarter including VAT. Under the flat rate scheme at 12.5%, you pay HMRC £60,000 x 12.5% = £7,500. You keep the remaining £2,500 (the difference between the 20% you charged and the 12.5% you pay).
There is a catch. If you are a "limited cost trader" (meaning you spend less than 2% of your turnover on relevant goods), you must use a flat rate of 16.5%. Most agencies fall into this category because their main costs are staff salaries and software, not physical goods. Check your position carefully before joining the scheme.
The flat rate scheme is available if your expected VAT-taxable turnover is £150,000 or less in the next 12 months. You can leave the scheme at any time, but you must leave if your turnover exceeds £230,000.
How to Handle Retainers and Project Fees
Retainers are straightforward. If you charge a client £4,000 per month excluding VAT, your invoice shows £4,000 plus £800 VAT, total £4,800. You record the £800 as output VAT on your VAT return.
Project fees can be trickier if you invoice in stages. Suppose you have a £12,000 project (excluding VAT) with three milestone invoices of £4,000 each. Each invoice includes £800 VAT. The total VAT over the project is £2,400. You account for it as you invoice, not when the project starts or ends.
If you receive a deposit or advance payment, VAT is due on the deposit at the time you receive it. You cannot delay the VAT until the project is complete.
Reclaiming VAT on Agency Costs
As a VAT-registered business, you can reclaim VAT on most business purchases. The VAT you pay is usually the difference between any VAT you have paid to other businesses and the VAT you have charged your customers [1]. If you have charged more VAT than you have paid, you pay the difference to HMRC [1]. If you have paid more VAT than you have charged, HMRC refunds you the difference.
Common reclaimable costs for agencies include:
- Software subscriptions (Adobe, Xero, Asana, etc.)
- Office rent and utilities
- Equipment (laptops, monitors, cameras)
- Professional services (accountants, lawyers, consultants)
- Travel and subsistence (hotels, train fares, client meals)
You cannot reclaim VAT on client entertaining (meals with clients are generally not reclaimable). You also cannot reclaim VAT on costs used for exempt supplies (like financial services, which most agencies do not deal with).
VAT on International Clients
If your agency works with clients outside the UK, the VAT treatment changes. For services to businesses in other EU countries, the place of supply is usually where the customer belongs. You do not charge UK VAT. Instead, the customer accounts for VAT in their own country under the reverse charge mechanism.
For services to businesses outside the EU, you generally do not charge UK VAT. The export of services is outside the scope of UK VAT.
For services to consumers (non-business clients) in other countries, the rules vary. If you sell digital services to EU consumers, you may need to register for VAT in the EU under the One Stop Shop (OSS) scheme. This is a niche area. If you have international clients, speak to your accountant before invoicing.
How to Complete a VAT Return
Your VAT return (form VAT100) asks for nine boxes of information. The key ones for agencies are:
- Box 1: VAT due on sales (the total output VAT you charged).
- Box 4: VAT reclaimed on purchases (the total input VAT you paid).
- Box 5: Net VAT to pay or reclaim (Box 1 minus Box 4).
- Box 6: Total value of sales excluding VAT.
- Box 7: Total value of purchases excluding VAT.
Most accounting software (Xero, QuickBooks, FreeAgent) calculates these boxes automatically from your transactions. You still need to review the numbers before submission. Common errors include missing a sales invoice, double-counting a purchase, or misclassifying a cost as reclaimable when it is not.
You submit the return online through your HMRC business tax account. Payment is due by the same deadline as the return, usually one calendar month and seven days after the end of the VAT period.
Common VAT Mistakes Agency Founders Make
Mistake 1: Not registering on time. If your turnover hits £90,000 and you do not register, HMRC can charge penalties and backdate the VAT you should have charged. Monitor your rolling 12-month turnover monthly.
Mistake 2: Charging VAT on everything. Some agency services are exempt or zero-rated. For example, training services can be exempt in certain circumstances. Check the VAT treatment of each service you offer.
Mistake 3: Forgetting to reclaim VAT on expenses. If you pay for a business expense with a personal card and do not enter it into your accounting system, you lose the VAT reclaim. Use a business card or a receipt capture app like Dext.
Mistake 4: Using the wrong flat rate percentage. If you are on the flat rate scheme and your sector changes (e.g., you move from marketing to consultancy), you must update your rate with HMRC.
Should You Use Standard Accounting or the Flat Rate Scheme?
For most agencies with significant costs (software, subcontractors, office space), standard accounting is better. You reclaim VAT on your costs, which can be substantial. The flat rate scheme is better if you have low costs and want simplicity. A 12-person digital agency billing £800k per year with £200k in costs will likely benefit from standard accounting. A sole trader web designer turning over £65k with minimal costs might prefer the flat rate scheme.
Run the numbers both ways before deciding. Your accountant can model this for you. If you are not sure, start with standard accounting. You can switch to the flat rate scheme later if it makes sense.
Final Thoughts
VAT calculation for your agency is not complicated once you understand the mechanics. The key numbers are 1.2 (to add VAT) and 1.2 (to remove VAT). The key rule is to account for VAT when you invoice, not when you get paid. The key habit is to check your rolling turnover every month.
If your contractor mix has changed in the last 12 months, or if you have started working with international clients, ask your accountant before your next VAT return. The rules around place of supply and reverse charge can catch you out.
For more guidance on agency-specific tax and compliance topics, visit our services page or explore our tax and compliance blog. If you are ready to discuss your agency's VAT position, contact us for a consultation.
Sources
- gov.uk: How VAT works: Overview - GOV.UK
- aka.hmrc.gov.uk: Charge, reclaim and record VAT - GOV.UK