When Should You Stop Using SumUp, Square or Zettle? A UK Business Guide

Find out when UK businesses should switch from SumUp, Square or Zettle, compare card machine fees and discover when a merchant account could save money.

8/24/202614 min read

When Should You Stop Using SumUp, Square or Zettle? A UK Business Guide
When Should You Stop Using SumUp, Square or Zettle? A UK Business Guide

When Should You Stop Using SumUp, Square or Zettle? A UK Business Guide

If you are a UK business owner, there is a good chance you started taking card payments using a provider such as SumUp, Square or Zettle.

They have become incredibly popular because they make accepting card payments simple. You can usually purchase a card machine without a lengthy application process, start taking contactless payments quickly and avoid many of the traditional barriers that existed when merchant services were much more complicated.

For many businesses, that is exactly the right choice.

However, as your business grows, your card processing costs grow with it.

A transaction fee that feels insignificant when you are processing £1,500 per month can become one of your largest operating expenses when you are processing £20,000, £50,000 or even £100,000 in card payments every month.

That does not mean SumUp, Square or Zettle are bad providers.

It simply means there comes a point where every business should ask an important question:

Am I still using the cheapest and most suitable card payment solution for my business?

This guide explains when it may be worth comparing alternatives, how merchant account pricing differs from flat-rate providers, how to calculate your real card processing costs and how Cheap Card Machines can help UK businesses find the most suitable payment solution.

Why SumUp, Square and Zettle are so popular

There is a reason these providers dominate the small business card machine market.

They have removed much of the complexity traditionally associated with accepting card payments.

Instead of speaking to acquiring banks, arranging merchant facilities and renting expensive terminals, many businesses can simply purchase a card reader and begin accepting payments.

For new businesses especially, this can be extremely appealing.

Typical benefits include:

  • Purchasing a card machine outright

  • Little or no monthly terminal rental

  • Straightforward transaction pricing

  • Contactless payment acceptance

  • Apple Pay and Google Pay compatibility

  • Portable card machines for mobile businesses

  • Simple apps and reporting dashboards

  • Quick setup for many eligible businesses

This flexibility has made these providers particularly popular with:

  • Sole traders

  • Market traders

  • Hairdressers

  • Beauty businesses

  • Mobile professionals

  • Cafés

  • Independent retailers

  • Tradespeople

  • Start-up businesses

  • Seasonal businesses

If your business processes relatively small amounts by card, simplicity can often be more valuable than shaving a fraction off your transaction costs.

The challenge comes when turnover begins increasing.

The point where convenience can become expensive

Imagine two businesses.

Business A is a mobile dog groomer processing £2,000 per month in card payments.

Business B is an independent retailer processing £35,000 every month.

Both could be using exactly the same card machine.

Yet their payment requirements are completely different.

For the smaller business, paying a straightforward transaction fee without worrying about monthly rental might represent excellent value.

For the retailer, those transaction fees are now being applied to hundreds of thousands of pounds in annual card turnover.

That is why there is no universal answer to which card machine is cheapest.

The cheapest option depends on how much your business processes, how you accept payments and what features you need.

Rather than asking which provider has the lowest advertised rate, businesses should instead ask:

  • What is my total annual card processing cost?

  • How much am I paying in transaction fees?

  • Are there any hidden monthly charges?

  • Would another pricing model reduce my costs?

  • Do I need more than one terminal?

  • Has my business outgrown my current provider?

Those questions are much more valuable than simply comparing headline percentages.

Flat-rate card machines versus merchant accounts

Understanding the difference between these two pricing models is essential before deciding whether to switch.

Flat-rate card machine providers

Providers such as SumUp, Square and Zettle are generally associated with straightforward pricing structures.

Instead of every business negotiating its own acquiring agreement, eligible businesses can often pay a standard transaction percentage for card payments.

That makes costs easy to understand.

For example, if a provider charged an illustrative transaction fee of 1.69%, processing £1,000 in card payments would cost approximately £16.90.

Processing £5,000 would cost approximately £84.50.

Processing £10,000 would cost approximately £169.

Processing £50,000 would cost approximately £845.

These are simply examples to demonstrate the maths rather than quotes from any provider.

The important thing to recognise is that percentages scale with turnover.

A fee that feels affordable at lower volumes becomes considerably more significant as your business grows.

Traditional merchant accounts

Merchant accounts work differently.

Rather than applying one standard transaction percentage to every business, pricing can be tailored around your individual circumstances.

Factors often considered include:

  • Monthly card turnover

  • Annual turnover

  • Average transaction value

  • Number of transactions

  • Industry

  • Trading history

  • Previous card processing history

  • Card mix

  • Debit versus credit cards

  • Consumer versus commercial cards

  • UK versus international transactions

  • Face-to-face versus remote payments

  • Chargeback history

This means merchant account pricing can appear more complicated.

However, complexity is not necessarily a disadvantage.

For businesses processing larger volumes, individually priced acquiring can sometimes provide significantly better value than remaining on a flat-rate structure.

The only way to know is by comparing the complete cost.

At what turnover should you compare providers?

There is no magic number.

Every business is different.

However, there are sensible turnover ranges where reviewing your card payment setup becomes increasingly worthwhile.

Businesses processing under £2,000 per month

If your monthly card turnover is below approximately £2,000, staying with a straightforward card machine provider may make perfect sense.

Why?

Because avoiding fixed monthly costs can often outweigh the benefit of negotiating a slightly lower transaction rate.

Imagine a business processing £1,500 each month.

Using an illustrative rate of 1.69%, the monthly processing cost would be around £25.35.

Even if another provider offered lower transaction pricing, additional terminal rental and service charges could quickly eliminate any saving.

Businesses in this category often include:

  • New businesses

  • Sole traders

  • Freelancers

  • Mobile businesses

  • Market stalls

  • Seasonal traders

  • Small independent retailers

At this stage, flexibility is often more valuable than optimisation.

Businesses processing between £2,000 and £5,000 per month

Once your card turnover becomes more consistent, it is worth understanding exactly what you are paying.

At £5,000 per month, an illustrative 1.69% processing fee equals around £84.50.

Across a year, that becomes more than £1,000.

That does not automatically mean you should leave your current provider.

It simply means you have reached a point where comparing the market becomes sensible.

You may discover that your current provider remains the best option.

Alternatively, you may find a merchant account offering a lower overall annual cost.

Either result is useful.

Businesses processing between £5,000 and £10,000 per month

This is where card processing becomes a meaningful business expense.

At £10,000 per month, a 1.69% illustrative transaction rate would represent approximately £169 every month.

That equates to more than £2,000 annually.

Even relatively small reductions in your effective processing cost can now create worthwhile savings.

For example, reducing your overall effective rate by the equivalent of 0.3% on £10,000 monthly turnover would represent approximately £30 every month before considering any additional charges.

Over a year, that is around £360.

Again, this is not a guarantee that switching will save money.

It simply demonstrates why businesses should start comparing total costs rather than relying on the provider they originally chose.

Businesses processing over £10,000 per month

Once your business is regularly processing five figures every month, reviewing your merchant services should become part of your normal business housekeeping.

Consider a retailer processing £25,000 monthly.

That is £300,000 annually in card turnover.

A relatively small difference in effective processing costs can become thousands of pounds over the course of a year.

Businesses processing at this level should regularly compare:

  • Transaction pricing

  • Terminal costs

  • Monthly charges

  • Contract terms

  • Settlement times

  • Integration options

  • Customer support

The more money moving through your card machines, the more important those details become.

How to calculate your real card processing costs

Many businesses only look at their transaction percentage.

That is a mistake.

The real cost of accepting card payments is your total processing expense.

A simple calculation can help.

Total card processing costs ÷ total card turnover × 100 = effective processing rate

Imagine your business processed £18,000 in card payments last month.

Your total card-related charges were £288.

Your effective processing rate would be:

288 ÷ 18,000 × 100 = 1.6%

That figure is far more useful than simply remembering your advertised transaction percentage.

When calculating your total costs, include everything you pay for card processing.

This could include:

  • Transaction fees

  • Card machine rental

  • Monthly service charges

  • PCI compliance fees

  • Gateway charges

  • Authorisation fees

  • Statement fees

  • Additional terminal charges

  • Minimum monthly fees

Only once everything has been included can you accurately compare providers.

Why the lowest transaction rate does not always win

A common mistake is assuming the provider with the lowest advertised percentage is automatically the cheapest.

It rarely works that simply.

Imagine Provider A offers an attractive transaction rate of 0.85%.

Provider B charges 1.2%.

Provider A appears considerably cheaper.

However, Provider A also includes:

  • £20 monthly terminal rental

  • £15 monthly service charge

  • Additional authorisation costs

  • PCI compliance charges

Provider B includes none of those.

For a low-turnover business, Provider B could actually cost less overall despite having the higher transaction percentage.

This is why every business should compare annual costs rather than individual pricing elements.

A card machine should be judged on the complete package.

Signs you may have outgrown your current provider

Turnover is important, but it is not the only reason businesses change payment providers.

Here are some common signs that it might be time to compare alternatives.

Your business has grown significantly

Perhaps you started as a market trader.

Now you have a permanent shop.

Or perhaps your online following has grown and your physical sales have doubled.

The card machine that was perfect two years ago may no longer be the most competitive option.

Growth should always trigger a review.

You now need multiple card machines

Many businesses begin with one terminal.

As they expand, they need additional devices for:

  • Multiple tills

  • Restaurant tables

  • Different staff members

  • Pop-up locations

  • Additional shops

The cost structure for multiple terminals can differ considerably between providers.

It is worth comparing the complete package rather than simply purchasing more of the same machines automatically.

You need better EPOS integration

Integrated card payments can save businesses considerable time.

Instead of manually entering the transaction value into a card machine, the EPOS system can automatically send the amount to the terminal.

Benefits can include:

  • Faster checkout

  • Fewer keying mistakes

  • Easier reconciliation

  • Better reporting

  • Improved customer experience

If your business has introduced an EPOS system, it may also be worth reviewing whether your card machine integrates properly.

Your reporting requirements have changed

A sole trader may only need to know today's sales.

A growing retailer may require detailed reporting across several locations.

You may now want visibility over:

  • Individual terminals

  • Staff performance

  • Daily settlement

  • Refunds

  • Transaction volumes

  • Multiple business locations

Different providers offer very different reporting capabilities.

The cheapest card machine is not always the best business tool.

Your settlement needs have changed

Cash flow is incredibly important for small businesses.

Understanding when card payments reach your business bank account should form part of any comparison.

Different providers may offer different settlement arrangements depending on their service.

If faster or more predictable settlement is important to your business, that should be considered alongside pricing.

Should you stop using SumUp?

SumUp remains a perfectly sensible choice for many UK businesses.

You should not switch simply because another company claims to be cheaper.

Instead, compare your actual costs.

SumUp may still be suitable if:

  • Your turnover remains relatively low

  • Your monthly sales fluctuate significantly

  • You want to avoid fixed terminal rental

  • You value straightforward pricing

  • You only require one or two terminals

  • The existing software meets your needs

It may be worth comparing alternatives if:

  • Your monthly card turnover has increased substantially

  • Your annual processing costs are becoming significant

  • You need multiple terminals

  • You want individually negotiated merchant rates

  • You require advanced EPOS integration

  • Your business has expanded into multiple locations

The goal is not necessarily to leave SumUp.

The goal is to make sure it remains competitive for your business today.

Should you stop using Square?

Square is slightly different because it offers a wider ecosystem beyond card machines.

Many businesses use Square for:

  • Point of sale

  • Inventory

  • Staff management

  • Invoicing

  • Online payments

  • Reporting

That additional functionality has genuine value.

Switching providers to save a small amount on transaction costs may create additional software expenses elsewhere.

Instead, compare your complete payment infrastructure.

Ask yourself:

  • Which Square features do I genuinely use?

  • Would another provider require separate EPOS software?

  • How much do I spend annually on card processing?

  • What would an alternative setup cost altogether?

  • Would changing provider improve or worsen operational efficiency?

A payment provider should support the whole business rather than simply offering the lowest percentage.

Should you stop using Zettle?

Zettle continues to be a popular choice for independent businesses wanting straightforward card payments.

For lower-turnover businesses, it may remain excellent value.

For growing businesses, the same principle applies.

Calculate your effective processing rate and compare the complete cost against alternative providers.

The decision should be based on evidence rather than assumptions.

Seasonal businesses should compare annual costs

Seasonal businesses face a slightly different challenge.

Imagine a Christmas retailer.

Most of its sales happen between October and December.

The business may process very little card turnover during spring and summer.

A merchant account with fixed monthly costs might look attractive during peak trading but become less appealing across the quieter months.

Alternatively, a pay-as-you-go provider may cost more during December but less over the full year because there are no ongoing rental costs.

For seasonal businesses, always compare annual expenditure.

Do not make decisions based on your busiest month alone.

New businesses should avoid overcomplicating things

If you have just launched your business, predicting future card turnover can be difficult.

You might estimate £10,000 monthly sales and actually process £2,500.

Or the opposite could happen.

That uncertainty is why many new businesses begin with a simple, flexible card machine before reviewing their options once they have established processing history.

After several months, you should have useful data including:

  • Average monthly card turnover

  • Number of transactions

  • Average transaction value

  • Busy periods

  • Refund levels

  • Card versus cash sales

  • Annual processing costs

Real trading data is much more valuable than forecasts when comparing merchant services.

What should you compare before switching card machine provider?

If you decide it is time to compare providers, make sure you are comparing like-for-like.

Transaction fees

Understand exactly what rate applies to different payment types.

Ask whether pricing differs for:

  • UK debit cards

  • UK credit cards

  • Commercial cards

  • International cards

  • American Express

  • Telephone payments

  • Online payments

A headline rate may not apply to every transaction.

Terminal costs

Some providers sell terminals outright.

Others rent them monthly.

Calculate the annual hardware cost rather than just the monthly figure.

For example:

£15 monthly rental equals £180 annually.

Three terminals equal £540 annually.

Those costs quickly add up.

Contract terms

Always understand the commitment you are entering.

Check:

  • Contract length

  • Early termination charges

  • Notice periods

  • Renewal terms

  • Replacement terminal policies

A cheap introductory deal is less attractive if leaving becomes expensive later.

PCI compliance

PCI DSS is an important part of accepting card payments securely.

Ask providers what support they provide and whether there are any associated charges.

Do not assume every provider structures this in the same way.

Settlement times

Knowing when money reaches your account is essential.

Compare settlement arrangements alongside pricing.

Better cash flow can sometimes be more valuable than a tiny difference in transaction fees.

Customer support

Your card machine failing during a busy Saturday can cost more than a few pounds in transaction fees.

Compare support options including:

  • Telephone availability

  • Technical support

  • Replacement terminals

  • Weekend assistance

  • Online account management

Reliable support is part of the overall value proposition.

Can you negotiate card machine fees?

Businesses with established card processing history may have greater opportunities to access individually priced merchant services.

If you are already processing cards, your recent acquiring statements can provide valuable information when comparing providers.

They demonstrate your genuine trading history including:

  • Monthly turnover

  • Number of transactions

  • Existing processing charges

  • Card mix

  • Refund activity

  • Processing history

This allows providers to assess your business more accurately.

Rather than simply asking for the cheapest rate, request a complete cost comparison based on your real processing data.

That produces a much more meaningful quote.

How Cheap Card Machines can help your business

Cheap Card Machines was created to help UK businesses make better decisions when choosing card payment solutions.

The biggest problem many business owners face is not finding card machines.

There are hundreds available.

The real challenge is understanding which solution is genuinely the best value for their individual business.

That is where we aim to help.

We compare more than just card machine prices

A cheap card machine is not always the cheapest payment solution.

A £29 card reader with higher transaction costs could become more expensive than a premium terminal if your business processes substantial turnover every month.

Our goal is to help businesses compare the complete picture rather than focusing on a single headline price.

We look at factors including:

  • Card machine purchase costs

  • Monthly terminal fees

  • Transaction charges

  • Merchant account pricing

  • Contract flexibility

  • EPOS compatibility

  • Mobile versus countertop terminals

  • Settlement arrangements

  • Business suitability

This helps businesses choose a payment solution based on how they actually trade.

We help businesses find the cheapest suitable option

There is an important difference between the cheapest product and the cheapest suitable product.

A market trader processing £1,000 monthly has different requirements from a restaurant processing £60,000.

Rather than recommending one provider for everyone, Cheap Card Machines helps businesses understand which type of solution is likely to provide the best overall value.

Depending on your circumstances, that could mean:

  • A no monthly fee card machine

  • Purchasing a terminal outright

  • A traditional merchant account

  • An integrated EPOS payment solution

  • A portable mobile card machine

  • Multiple terminals for a growing business

The recommendation should always reflect the business rather than the marketing.

We explain the confusing parts in plain English

Merchant services are often unnecessarily complicated.

Businesses are regularly confronted with terminology such as:

  • Merchant accounts

  • Acquiring banks

  • Interchange

  • PCI compliance

  • Authorisation fees

  • Gateway charges

  • Settlement

  • Chargebacks

Our website is designed to explain these topics clearly so business owners can make informed decisions without needing an industry background.

If you are unsure what a card machine actually costs, our guides can help break down the different pricing models and explain what you should look for before signing an agreement.

We support businesses that are growing

Many businesses visit Cheap Card Machines because they originally bought the first card reader they found online.

That is completely understandable.

As turnover grows, they begin questioning whether they are paying too much.

Reviewing your card processing costs does not mean you have made a bad decision previously.

It simply means your business has changed.

We help businesses reassess their options based on their current turnover, requirements and future plans.

Our wider merchant services expertise

Cheap Card Machines is part of the wider Payments World network, allowing businesses to access additional information about merchant services, payment gateways, online payments and business payment solutions.

If your requirements extend beyond simply purchasing a card machine, you can also visit Payments World for further guides and information covering merchant accounts, acquiring, online payment gateways and card processing for UK businesses.

This can be particularly useful for businesses operating both in-store and online, or those looking to understand the wider payments industry before choosing a provider.

When should you review your card processing?

For most established businesses, reviewing your payment costs once every year is sensible.

You should also consider comparing providers whenever there is a significant change in your business.

Examples include:

  • Opening another location

  • Increasing turnover substantially

  • Hiring more staff

  • Introducing EPOS

  • Adding additional terminals

  • Launching online sales

  • Reaching the end of a contract

  • Receiving a pricing increase

  • Changing your business model

Reviewing does not mean switching.

Sometimes your existing provider will remain the best value.

The purpose is simply ensuring your payment solution continues to suit the business you are running today rather than the business you operated two years ago.

Frequently asked questions

When should I switch from SumUp to a merchant account?

There is no fixed turnover where switching becomes essential. However, once your business is consistently processing several thousand pounds each month, it is sensible to compare your current annual processing costs against merchant account alternatives. The higher your turnover, the more meaningful relatively small differences in effective processing costs become.

Is SumUp cheaper than a traditional merchant account?

It can be, especially for lower-turnover businesses that benefit from avoiding fixed monthly charges. Businesses processing larger volumes may find that individually negotiated merchant account pricing provides better overall value. The only reliable way to know is by comparing the complete annual cost.

Is Square worth keeping as my business grows?

Square may remain excellent value if you use its wider software ecosystem including EPOS, inventory and invoicing. Rather than comparing transaction fees alone, calculate the total cost of your complete payment setup before deciding whether changing provider would genuinely save money.

Should I change from Zettle if I process more than £10,000 per month?

Not necessarily. Processing more than £10,000 monthly simply means it becomes increasingly worthwhile to compare your effective processing costs against alternative providers. Your current setup may still represent the best overall value depending on your business requirements.

How do I calculate my effective card processing rate?

Divide your total card processing costs by your total card turnover and multiply by 100. Include every relevant fee including transaction charges, terminal rental, monthly service fees and other processing costs to create an accurate comparison.

Are no monthly fee card machines always cheaper?

No. They can be excellent value for low-volume or seasonal businesses because they avoid fixed costs. However, businesses with higher card turnover may find that a solution with monthly charges but lower transaction costs provides better overall annual value.

Can Cheap Card Machines help me compare providers?

Yes. Cheap Card Machines provides information and guidance to help UK businesses understand card machine pricing, merchant services and the different payment options available. Our aim is to help businesses identify the most suitable and cost-effective solution based on how they trade rather than simply choosing the lowest advertised price.

Conclusion

Choosing a card machine is not a decision you make once and forget forever.

The payment solution that works perfectly for a brand-new business may become less competitive as turnover increases, additional staff are hired or multiple locations open.

SumUp, Square and Zettle have all made accepting card payments significantly easier for UK businesses, and for many companies they continue to provide excellent value. There is no reason to switch purely because your business has grown.

What matters is understanding what you are actually paying.

By calculating your effective processing rate, reviewing your annual card costs and comparing the complete package rather than just the headline transaction percentage, you can make a far more informed decision about whether your existing provider is still right for your business.

At Cheap Card Machines, our focus is helping UK businesses understand the real cost of accepting card payments. Whether you are looking for a cheap card machine with no monthly fee, comparing portable terminals, exploring merchant accounts or reviewing your current processing costs, our guides are designed to make merchant services easier to understand.

If your business has grown since you first started taking card payments, now is a sensible time to review your options. The cheapest card machine is not always the one with the lowest purchase price or the lowest advertised transaction rate. It is the payment solution that delivers the best overall value for the way your business operates today.