🏠 Payment Processing» What Is a Merchant Account? A Plain-English Guide for UK Businesses
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What Is a Merchant Account? A Plain-English Guide for UK Businesses
A merchant account lets you accept card payments. Most small businesses use a PSP like Square or SumUp, no dedicated account needed.
A merchant account is a type of bank account that allows a business to accept card payments. When a customer pays by card, the funds are held temporarily in the merchant account before being transferred to your business bank account.
Most small UK businesses never see this layer directly. Payment service providers like Square and SumUp manage it on your behalf.
BusinessExpert may earn a commission if you sign up through links on this page. Square and SumUp are affiliate partners. Our editorial recommendations are based on verified pricing and features, not commission rates.
What is a merchant account and how does it work?
The payment flow for a card transaction has several steps: the customer’s card is read, the card network (Visa or Mastercard) checks the available funds, the transaction is authorised, and the funds are reserved in the merchant account.
Settlement typically happens 1–2 working days later, once the funds transfer from the merchant account to your bank.
Traditionally, a merchant account required a separate application to an acquiring bank (Worldpay, Barclays, NatWest). The acquirer underwrites your business, approves the account, and charges a monthly fee plus a per-transaction rate. This process can take weeks.
Merchant account vs payment service provider: what is the difference?
A payment service provider (PSP) like Square, SumUp, or Stripe pools thousands of merchants into a single acquiring relationship. You do not need your own merchant account, the PSP gives you access to its. In exchange:
Sign-up is instant, often under five minutes
No underwriting or credit checks in most cases
Flat transaction rates (no interchange-plus complexity)
The PSP can suspend or terminate your account if you breach their terms
A dedicated merchant account from an acquirer gives you more control, potentially lower rates at volume, and a direct commercial relationship. The trade-off is a longer setup process and a contractual commitment.
Not a dedicated one. For most small UK businesses, sole traders, limited companies, hospitality, retail, professional services, a PSP handles everything a merchant account does without the setup friction. The question is really which PSP fits your volume and business type.
A dedicated merchant account is worth considering if you process £200,000+ per year in card sales, operate in a sector that PSPs flag as high-risk, or need contractual rate guarantees over 12–36 months.
Merchant account providers
Square Reader
Top Pick
Top Pick
Square Reader
The right reader for any business that cannot honestly forecast its card volume a year out.
Not ideal if: High-volume sellers who would benefit from Dojo or other negotiated per-transaction rates
Transaction fee1.75% flat (all cards incl. Amex)
Monthly feeNone
Hardware cost£19 +VAT
SettlementNext working day (1–2 days standard)
ContractNo lock-in
Amex acceptedYes: same 1.75% rate
Eligibility: UK businesses: sole traders, partnerships, and limited companies. Account holders must be 18 or over. Custom rates available for businesses processing over £200,000 annually. Prohibited categories include firearms and other restricted activities: see Square’s Acceptable Use Policy.
Not ideal if: High-volume sellers who would benefit from Dojo or other negotiated per-transaction rates
If you use a PSP like Square or SumUp, you can be ready to take payments within minutes of sign-up. A dedicated merchant account from a traditional acquirer typically takes 5–10 business days for approval, with additional time for hardware delivery.
Can a sole trader get a merchant account?
Yes. PSPs accept sole traders with no minimum turnover requirement. Traditional acquirers may require a business bank account and trading history. If you are a sole trader starting out, Square, SumUp, or Tide Card Reader are your fastest routes to accepting card payments.
What is interchange-plus pricing?
Interchange-plus (or cost-plus) pricing splits the rate into the card network interchange fee (set by Visa/Mastercard) plus the acquirer’s margin. It is more transparent than flat-rate pricing and usually cheaper at volume. If you process above £200,000 a year in card sales, you may find interchange-plus cuts your total rate compared to a flat-rate PSP. Traditional acquirers may offer interchange-plus at higher volumes.
What is a payment gateway?
A payment gateway is the software that connects your online checkout to the card network. For in-person payments, the card reader is the gateway. For online payments, providers like Square, Stripe, and GoCardless provide a gateway as part of their service. A merchant account is the account that holds funds; the gateway is the technology that routes the transaction. We cover the main gateway options in our best payment gateway guide.
How we reviewed this
What we covered. We explain what a merchant account actually is, how money moves from a customer’s card to your bank, and where the fees get taken out, using acquirer and PSP documentation alongside FCA guidance current in May 2026.
Data sources. We traced the real fee structures and settlement terms straight from provider and acquirer pricing pages in May 2026, and we confirmed regulatory status against the FCA register.
Update cadence. We re-verify this page at least monthly, and whenever a provider changes pricing, eligibility, or terms. The verification date on the page reflects the most recent full review. Some links on this page are affiliate links, see our editorial policy.