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Accounting · head to head

Carta vs IRIS KashFlow

Carta logo

Carta

Accounting

Cap table, equity and 409A valuation software built around United States private company practice

From
$29/month
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: Carta pricing scales with the number of stakeholders on the cap table, so a company that grants options broadly pays a rising annual fee for employees and small angels who sign in once a year, and the cost keeps climbing after the round that justified it is spent.; 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 Carta and IRIS KashFlow actually diverge.

Attributes where Carta and IRIS KashFlow differ
AttributeCartaIRIS KashFlow
Starting price$29/month£13.5/month
PlatformsWeb, Ios, AndroidWeb
Founded2012Unknown

Identical on both: pricing model (subscription), 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 Carta

  • Cap table of record
  • 409A valuations
  • Electronic issuance
  • Vesting and exercise
  • Employee portal
  • Scenario modelling
  • Waterfall analysis
  • ASC 718 expense reporting

Only in IRIS KashFlow

Nothing recorded that Carta does not also cover.

What people use each for

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

Carta

  • A startup that has just closed a priced round and whose investors and counsel expect the cap table to live somewhere they can read itnot IRIS KashFlow
  • A company issuing options to employees for the first time and needing a defensible 409A before it can set a strike pricenot IRIS KashFlow
  • A finance team preparing its first audit and needing ASC 718 stock compensation schedules that tie to the grant recordsnot IRIS KashFlow
  • A venture fund that wants LP reporting, capital calls and SPV administration handled outside a spreadsheetnot IRIS KashFlow

IRIS KashFlow

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

Where each one falls short

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

Carta

  • Pricing scales with the number of stakeholders on the cap table, so a company that grants options broadly pays a rising annual fee for employees and small angels who sign in once a year, and the cost keeps climbing after the round that justified it is spent.
  • The cap table is a legal record assembled from years of board consents, so migrating to another provider means re-entering historical transactions and having counsel confirm the rebuilt table matches the signed documents, which is why most companies stay whatever they think of the service.
  • The product is built around United States company law and tax practice, Delaware entities, 409A and ASC 718, so a company incorporated in the United Kingdom, Europe or elsewhere gets a record keeping tool while the valuation and compliance features that carry the price are of limited or no use.
  • 409A valuations are delivered on a cadence and require a refresh after each material event or every twelve months, so a company that raises or changes materially is repeatedly back in a valuation process with fees and turnaround time attached, and a late valuation blocks option issuance.
  • Carta drew sustained criticism in 2024 over how customer cap table data intersected with its secondary trading business, and although it exited that activity the episode is a live reason to check what a vendor holding your ownership record is permitted to do with it.

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

Carta

$29/month
  • LaunchFree
    • Cap table
    • Stakeholder management
  • Seed$360/year
    • 409A valuations
    • Option exercising
    • Scenarios

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 Carta if

  • You need cap table of record.
  • You work on Web, Ios, Android.
  • You also want 409a valuations.
Carta review

Choose IRIS KashFlow if

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

IRIS KashFlow review

Questions people ask

Is Carta or IRIS KashFlow better?
Neither clearly leads. Carta starts at $29/month 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, Carta or IRIS KashFlow?
Carta starts at $29/month and IRIS KashFlow at £13.5/month.
Does Carta or IRIS KashFlow run on more platforms?
Carta runs on Web, Ios, Android. IRIS KashFlow runs on Web.
What is Carta best used for?
Carta is most often used for a startup that has just closed a priced round and whose investors and counsel expect the cap table to live somewhere they can read it, a company issuing options to employees for the first time and needing a defensible 409a before it can set a strike price, a finance team preparing its first audit and needing asc 718 stock compensation schedules that tie to the grant records, a venture fund that wants lp reporting, capital calls and spv administration handled outside a spreadsheet. Of those, a startup that has just closed a priced round and whose investors and counsel expect the cap table to live somewhere they can read it and a company issuing options to employees for the first time and needing a defensible 409a before it can set a strike price are not what IRIS KashFlow is typically brought in for.
What can Carta do that IRIS KashFlow cannot?
Carta covers Cap table of record, 409A valuations, Electronic issuance, Vesting and exercise.

Answered from the vendors’ own pages

Carta: Do I need Carta before I have employees with options?

No. Before options exist a spreadsheet reviewed by your lawyer is usually enough. The pressure to move normally comes at a priced round, or the first time you need a 409A to set a strike price.

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
Carta: Is the 409A included in the subscription?

The subscription tiers bundle valuations differently and refreshes after material events can carry additional cost. Check what triggers a chargeable revaluation before you sign, because raising a round is exactly the moment you will need one.

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
Carta: Can my accountant get the stock compensation numbers out of it?

Yes, it produces ASC 718 expense schedules and exports. If your accounts are prepared under a different framework, expect the schedules to be a starting point that your accountant reworks rather than something they post directly.

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
Carta: Is it useful for a company outside the United States?

It can hold the share register and grants, and it does support some non United States structures. The 409A and United States tax workflow will not apply to you, so weigh it against local alternatives that understand your filings.

Carta: How hard is it to leave?

Harder than the export button suggests. You can export the data, but the receiving system has to reproduce every historical grant, cancellation and transfer, and someone has to verify the result against the original signed consents.

Carta: Who normally pays for it, the company or the investors?

The company, even though investors and counsel are frequent users. That is the usual complaint about the pricing model: the party paying is not the only party benefiting.

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