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Accounting · head to head

Adyen vs IRIS KashFlow

Adyen logo

Adyen

Accounting

The payments platform built for growth

From
$0.13/per-transaction
Rated
-
Full reviewWebsite
IRIS KashFlow logo

IRIS KashFlow

Accounting

Online accounting software for UK sole traders and small businesses

From
£13.5/month
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Adyen there is a minimum monthly invoice, set by industry and business model and only disclosed through the sales team, so small volumes are not economic; IRIS KashFlow advertised monthly prices of £1.35 (Starter) and £2.75 (Business) are a 90% promotional discount off the standard £13.50 and £27.50 rates, and the promotion is described as lasting 6 months before reverting
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Adyen and IRIS KashFlow actually diverge.

Attributes where Adyen and IRIS KashFlow differ
AttributeAdyenIRIS KashFlow
Starting price$0.13/per-transaction£13.5/month
Pricing modelusage-basedsubscription
PlatformsWeb, Api, PosWeb
Founded2006Unknown

Identical on both: free tier (No), user rating (Not yet rated), category (Accounting).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Adyen

  • Payment processing
  • Risk management
  • Unified commerce
  • Issuing
  • Platform payments
  • SAP
  • Salesforce
  • Oracle

Only in IRIS KashFlow

Nothing recorded that Adyen does not also cover.

What people use each for

The jobs each tool is most often brought in to do.

Adyen

  • Card acquiring with interchange plus pricing for larger merchantsnot IRIS KashFlow
  • Accepting local payment methods across multiple countriesnot IRIS KashFlow
  • Settling in several currencies through linked bank accountsnot IRIS KashFlow
  • Unified online and in-person paymentsnot IRIS KashFlow

IRIS KashFlow

  • business accountingnot Adyen
  • invoicing and billingnot Adyen
  • VAT managementnot Adyen

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Adyen

  • There is a minimum monthly invoice, set by industry and business model and only disclosed through the sales team, so small volumes are not economic
  • Published fees are indicative rather than a rate card, with real pricing negotiated
  • Interchange++ means the card cost varies per transaction rather than being a single predictable percentage
  • Alternative payment methods carry their own rates on top, such as 3.3 percent plus $0.10 for American Express in North America

IRIS KashFlow

  • Advertised monthly prices of £1.35 (Starter) and £2.75 (Business) are a 90% promotional discount off the standard £13.50 and £27.50 rates, and the promotion is described as lasting 6 months before reverting
  • Listed prices are in GBP plus VAT, and the platform's plans are built around UK VAT filing rather than other tax regimes
  • Annual pricing is quoted at RRP £162/year (Starter) and £291.50/year (Business) before the same promotional reduction

Pricing, plan by plan

Adyen

$0.13/per-transaction
  • Transaction-Based Pricing$undefined/mo
    • Fixed $0.13 USD per transaction
    • Variable fee determined by payment method
    • No setup fees

IRIS KashFlow

£13.5/month
  • Starter Monthly$13.5/month
    • 10 invoices
    • up to 25 bank transactions
    • single user access
  • Business Monthly$27.5/month
    • unlimited invoices
    • unlimited bank transactions
    • multi-user access
  • Starter Annual$162/year
    • 10 invoices
    • up to 25 bank transactions
    • single user access
  • Business Annual$291.5/year
    • unlimited invoices
    • unlimited bank transactions
    • multi-user access

Which should you pick?

Choose Adyen if

  • You need payment processing.
  • You work on Web, Api, Pos.
  • You also want risk management.
Adyen review

Choose IRIS KashFlow if

Nothing in the data separates IRIS KashFlow from Adyen on the points above - pick on price and on how each one feels to use.

IRIS KashFlow review

Questions people ask

Is Adyen or IRIS KashFlow better?
Neither clearly leads. Adyen starts at $0.13/per-transaction and IRIS KashFlow at £13.5/month, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Adyen or IRIS KashFlow?
Adyen starts at $0.13/per-transaction and IRIS KashFlow at £13.5/month.
Does Adyen or IRIS KashFlow run on more platforms?
Adyen runs on Web, Api, Pos. IRIS KashFlow runs on Web.
What is Adyen best used for?
Adyen is most often used for card acquiring with interchange plus pricing for larger merchants, accepting local payment methods across multiple countries, settling in several currencies through linked bank accounts, unified online and in-person payments. Of those, card acquiring with interchange plus pricing for larger merchants and accepting local payment methods across multiple countries are not what IRIS KashFlow is typically brought in for.
What can Adyen do that IRIS KashFlow cannot?
Adyen covers Payment processing, Risk management, Unified commerce, Issuing.

Answered from the vendors’ own pages

Adyen: How much does Adyen charge per transaction?

Adyen charges a fixed $0.13 USD per transaction plus a variable fee based on the payment method used. Credit cards typically cost $0.13 + 0.60% + interchange, while digital wallets and BNPL options cost between $0.13 + 0.99% to $0.13 + 4.99%+, depending on the specific method and region.

Source
IRIS KashFlow: What are IRIS KashFlow's core features across all plans?

All IRIS KashFlow plans include unlimited quotes, online VAT submission, mobile app access, 50+ reports, bank feeds, receipt capture, multi-currency support, and payroll for up to 5 employees.

Source
Adyen: Does Adyen have monthly subscription or setup fees?

No, Adyen has no setup fees or monthly recurring charges. You pay only for each transaction processed. The transaction fee structure remains the same regardless of transaction volume or business size.

Source
IRIS KashFlow: Are there promotional discounts for new IRIS KashFlow customers?

Yes, new customers receive a 90% discount for 6 months on both Starter and Business monthly plans.

Source
Adyen: What's Adyen's Interchange++ pricing option?

Adyen offers an Interchange++ transparent pricing model that passes interchange and scheme fees directly to merchants instead of bundling them into a percentage rate. This allows visibility into exact costs for each payment method.

Source
IRIS KashFlow: Can multiple users access IRIS KashFlow on the Starter plan?

No, the Starter plan is limited to single-user access only. Multi-user access requires the Business plan.

Source
Adyen: Can I process payments in multiple currencies with Adyen?

Yes, Adyen supports 100+ payment methods across multiple currencies. You can link multiple bank accounts in different currencies to avoid currency conversion fees on international transactions.

Source
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