How to Start a Marketplace Company in the UK (2026)

To start a marketplace company in the UK, register a limited company with Companies House, open a business bank account, and pick your legal model, agency or merchant of record, because it decides who owes VAT. Then build the platform, usually Shopify plus a multi-vendor app, and recruit your first vendors and buyers.

The mechanics of finding a niche, recruiting sellers, and choosing a business model are the same everywhere. What makes a UK marketplace different is the compliance layer: company registration, VAT and the online marketplace rules, payment regulation, and consumer law. This guide walks through that UK-specific setup, then the practical build. It is general information, not legal or tax advice, so confirm your own position with an accountant, a solicitor, HMRC and the FCA.

What you need to start a marketplace company in the UK

Here is the whole path at a glance. The rest of the guide covers each step in order.

1. Register your business structure (usually a limited company).
2. Decide who is the legal seller, and therefore who owes VAT.
3. Understand UK VAT and the online marketplace rules.
4. Set up payments without becoming a regulated payment institution.
5. Cover consumer law and data protection.
6. Build the platform (most operators use Shopify plus a multi-vendor app).
7. Recruit vendors and make your first sales.

Step 1: Register your UK business structure

You can trade as a sole trader or a limited company. Most marketplace founders pick a limited company, because it separates your personal money from the business and looks more credible to vendors handing you their sales.

Registering (incorporating) a company online through Companies House costs £100 as of February 2026, when the fee doubled from £50. A same-day paper filing costs more. You will need a company name, a registered UK address, at least one director, and details of shareholders. Sole traders skip Companies House and instead register for Self Assessment with HMRC.

Open a dedicated business bank account once you are incorporated. Several UK digital banks offer free or low-cost accounts, which matters when your first months are lean.

Step 2: Decide who is the legal seller, and who owes VAT

This is the decision that shapes everything downstream, and most first-time founders skip it. On a marketplace there are two sellers in the room: the vendor who ships the product, and you, the operator who runs the checkout. UK law needs to know which of you is legally selling to the buyer.

There are two common models:

• Agency model. The vendor is the legal seller. The buyer's contract is with the vendor, and the vendor is responsible for their own VAT. You take a commission and never legally own the money.
• Merchant of record. You are the legal seller. You collect payment in your own name, handle VAT, refunds and chargebacks, then pay vendors as your suppliers.

The choice affects your VAT position, your payment flow, and your paperwork. We cover the trade-offs in detail in agency vs merchant of record on Shopify. Pick one before you write a line of terms and conditions.

Step 3: Understand UK VAT and the online marketplace rules

Two separate VAT questions apply to a marketplace, and people constantly merge them.

Your own VAT registration. You must register for VAT once your taxable turnover passes £90,000 in any rolling 12-month period, a threshold unchanged since April 2024. For a commission-based marketplace, your "turnover" is usually your commission income, not the full value of goods sold, but that depends on your model, so confirm it. See gov.uk on when to register. You can also register voluntarily below the threshold to reclaim input VAT.

The online marketplace (deemed supplier) rules. Since 1 January 2021, HMRC can treat an online marketplace as the deemed supplier and make it collect and account for VAT on certain third-party sales, even in an agency setup. It bites mainly in two cases, per HMRC's guidance on overseas goods sold through online marketplaces:

• Imported consignments valued at £135 or less, sold to GB customers, where the goods are outside the UK at the point of sale.
• Goods of any value already in the UK at the point of sale, sold by an overseas seller.

In those cases the overseas seller is treated as making a zero-rated supply to you, and you charge the buyer UK VAT. If all your vendors are UK-based and VAT-registered, the deemed supplier rules are far less likely to apply, but a mixed or international vendor base changes the picture fast. If you sell across borders, tax and duty for a cross-border marketplace goes deeper on VAT, IOSS and customs.

Get an accountant before you open registrations to vendors abroad. This is the area where cheap mistakes become expensive ones.

Step 4: Set up payments without becoming a regulated payment institution

Here is the trap. The moment you collect a buyer's money into your own account and then pay it out to sellers, you may be providing a regulated payment service. Under the Payment Services Regulations 2017, a firm that holds or controls customer funds usually needs to be authorised by the FCA as a payment institution, with safeguarding rules that keep client money in segregated accounts. That is a heavy, slow, expensive authorisation for a business that just wants to run a shop.

Almost no small marketplace should take that on. The standard route is to let an established payment provider be the regulated party. Providers like Stripe Connect, Mollie, Airwallex and PayPal split each payment at checkout and pay each vendor their share directly, minus your commission, so the money never sits under your control as unregulated custody. The regulated entity holds the funds, not you.

Garnet Marketplace, a Shopify multi-vendor marketplace app, connects to those providers so payouts and commission splits run through the payment institution rather than through your own balance sheet. If you want the mechanics, how marketplace split payments work walks through the buyer-to-vendor flow, and the payment integrations page lists the supported providers. Still, confirm your specific arrangement with a solicitor or the FCA, because the details of who holds funds and for how long are what decide your regulatory status.

Step 5: Cover consumer law and data protection

UK consumer law applies to online sales whether you like it or not. The essentials:

• Consumer Rights Act 2015. Goods must be as described, fit for purpose and of satisfactory quality, and buyers get a short window to reject faulty goods. In an agency model this sits with the vendor, but your terms need to make that clear.
• Consumer Contracts Regulations 2013. Distance sellers must give buyers a 14-day cooling-off period to cancel most orders. Build returns handling that respects it.
• Data protection (UK GDPR and the Data Protection Act 2018). You hold personal data on buyers and vendors, so you need a privacy policy, a lawful basis for processing, and a way to honour data requests. Start from the ICO guidance.

You also need marketplace-specific paperwork that generic ecommerce stores skip: a vendor agreement setting commission, payout timing and each side's responsibilities, plus clear terms of sale. Templates cost little; a solicitor-drafted set costs more but protects you when a vendor dispute lands.

Step 6: Build the platform on Shopify

With the legal groundwork done, the build is the easy part. For a UK marketplace under roughly £30 million in revenue, hosted Shopify plus a multi-vendor app is the fastest reliable route, and it avoids the maintenance and security burden of self-hosting WooCommerce or a custom stack. You can build a marketplace on Shopify in days rather than the months a bespoke platform takes.

A multi-vendor app adds what a plain Shopify store lacks: vendor accounts and dashboards, per-vendor commission, split payouts, product moderation, and separate order routing to each seller. My Next Bike, a UK C2C cycling marketplace, runs exactly this setup on Garnet with a single login for buyers and sellers. That is the same shape most UK operators want: keep the Shopify checkout and payments buyers already trust, and layer the marketplace mechanics on top.

Pick a free Online Store 2.0 theme to launch, add your vendor onboarding and commission settings, connect your payment provider from Step 4, and you have a working marketplace.

Step 7: Recruit vendors and make your first sales

Two communities decide whether this works: buyers and sellers. Recruit both, but validate demand first. The founders who grow fastest tend to make their first few sales manually, by hand, before they spend on ads or a fancy theme, because it proves the products actually move.

Vendors are usually the easier side. Most sellers will happily pay a commission as long as you raise the retail price to match, so friction, not fees, is what loses them. The start your marketplace guide covers finding communities, defining commission and niching down in more depth; the UK-specific work is everything in Steps 1 to 5 above.

How much does it cost to start a marketplace business in the UK?

Marketplace start-up costs in the UK are lower than most people expect, because the platform is cheap and the real spend goes on compliance. Here is a realistic first-year picture for a lean Shopify-based launch.

Item	Typical UK figure	Notes
Company incorporation (Companies House, online)	£100 one-off	Rose from £50 in February 2026
Business bank account	£0 to £15 / month	Free digital accounts exist
Shopify plan	from ~£25 / month	Basic plan, UK pricing
Multi-vendor app (e.g. Garnet)	from ~£15 / month	Adds vendors, splits, payouts
Storefront theme	£0 to ~£300 one-off	Free themes work to launch
Accountant	£50 to £150 / month	Worth it near VAT registration
Terms, privacy and vendor agreements	£0 to £1,500	Templates vs solicitor-drafted
Domain name	~£10 / year	.co.uk or .com

The software adds up to about £40 to £60 a month. Everything above that is optional at launch and scales with the business. For a full breakdown across custom builds, SaaS and apps, see the cost of building a marketplace website.

Common mistakes when starting a UK marketplace

• Building before validating. A polished platform with no buyers is the most expensive way to learn your model does not work.
• Ignoring the seller-of-record question. Deciding agency vs merchant of record late means rewriting your terms, your payment flow and your VAT plan.
• Holding funds yourself. Collecting buyer money and paying vendors from your own account can pull you into FCA authorisation. Route it through a regulated provider.
• Skipping the vendor agreement. Handshake deals fall apart the first time a payout or a refund is disputed.
• Competing on price alone. A commission under 10% leaves nothing to run the business. Niche down so you can charge more.

Frequently asked questions

How do I start a marketplace business in the UK?

Register a limited company with Companies House, open a business bank account, and choose your legal model. Build the platform, most operators use Shopify with a multi-vendor app, connect a regulated payment provider so you never hold seller funds, publish your terms and privacy policy, and start recruiting vendors and buyers.

What is the best way to start a marketplace business in the UK?

Validate demand before you build. Make a handful of sales by hand, confirm vendors will accept your commission, then launch on Shopify with an app rather than paying for a custom build. That keeps your monthly cost under about £60 and puts your budget where it matters: an accountant and clean legal terms.

How much are marketplace start-up costs in the UK?

Plan for roughly £40 to £60 a month in software (Shopify plus a multi-vendor app), a one-off £100 to incorporate, an accountant from about £50 a month as you approach VAT registration, and £0 to £1,500 for legal documents depending on whether you use templates or a solicitor.

Do I need to register for VAT to run a marketplace in the UK?

You must register once your taxable turnover passes £90,000 in a rolling 12 months. Separately, the online marketplace rules can make you the deemed supplier for certain third-party sales, mainly imported consignments of £135 or less and UK-located goods sold by overseas sellers. Confirm your exact position with an accountant.

How do you create a successful marketplace business in the UK?

To create a successful marketplace in the UK, niche down so you can charge a healthy commission, keep vendor onboarding frictionless, and get the legal and payment setup right from day one. Stay close to both buyers and vendors so you learn what keeps them coming back.

Where can I get help starting a marketplace company in the UK?

For the compliance side, an accountant and a solicitor are worth their fee. For the build, Garnet has worked with hundreds of marketplaces, several based in the UK. Contact the team to talk through your model and see the platform.