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APIs · head to head

Formance vs Kotlin Multiplatform

Formance logo

Formance

APIs

Open source double-entry ledger and payment orchestration for money-moving software

From
Free
Rated
-
Full reviewWebsite
Kotlin Multiplatform logo

Kotlin Multiplatform

Mobile Development

JetBrains-funded technology for sharing Kotlin business logic across iOS, Android, web, desktop and server

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Formance formance holds no money and provides no regulatory cover, so it must be paired with a payments provider or bank, and buyers occasionally mistake a ledger for a treasury system and discover the gap late.; Kotlin Multiplatform it shares logic, not UI, by default, so a team expecting a Flutter-style single UI codebase has to also adopt Compose Multiplatform, which is newer and less proven on iOS than on Android.
  • They diverge on capability: Formance covers Double-entry ledger, Kotlin Multiplatform covers Shared Kotlin logic.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Formance and Kotlin Multiplatform actually diverge.

Attributes where Formance and Kotlin Multiplatform differ
AttributeFormanceKotlin Multiplatform
PlatformsLinux, Docker, Kubernetes, Web, APIiOS, Android, Windows, macOS, Linux, Web
CategoryAPIsMobile Development

Identical on both: starting price (Free), pricing model (Open source, no licence fee), free tier (Yes), user rating (Not yet rated).

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 Formance

  • Double-entry ledger
  • Numscript transaction DSL
  • Multi-currency
  • Payments connectivity
  • Reconciliation
  • Self-hosted deployment
  • Cloud offering
  • API and SDKs

Only in Kotlin Multiplatform

  • Shared Kotlin logic
  • Native UI retained
  • Compose Multiplatform (optional)
  • IDE tooling
  • Gradle-based builds
  • Incremental adoption

What people use each for

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

Formance

  • A marketplace splitting a single customer payment between seller, platform fee and tax that needs the split to be atomic and auditablenot Kotlin Multiplatform
  • A fintech whose homegrown balances table produced numbers finance could not reconcile and now needs proper double-entry before an auditnot Kotlin Multiplatform
  • A payments team that wants one normalised model across several PSPs so reconciliation is not written separately for eachnot Kotlin Multiplatform
  • A company that wants its ledger under a licence it can keep running even if the vendor disappearsnot Kotlin Multiplatform

Kotlin Multiplatform

  • A company with existing separate native iOS and Android codebases wanting to stop duplicating business logic and networking codenot Formance
  • A team that wants shared logic but is not willing to compromise on fully native UI per platformnot Formance
  • An organisation already using Kotlin on the backend that wants to reuse the same models and validation on mobile clientsnot Formance
  • A team evaluating Compose Multiplatform for UI sharing but wanting the option to fall back to native UI per screennot Formance

Where each one falls short

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

Formance

  • Formance holds no money and provides no regulatory cover, so it must be paired with a payments provider or bank, and buyers occasionally mistake a ledger for a treasury system and discover the gap late.
  • Numscript is a domain-specific language your team must learn, and while it makes complex splits expressible it also means transaction logic sits outside the languages your engineers already debug well.
  • Self-hosting a ledger that must never lose or duplicate a transaction is a serious operational commitment covering backups, upgrades and Postgres tuning, which is real cost the zero licence fee hides.
  • Enterprise pricing is not published, so the difference between the free path and the supported path cannot be evaluated without a sales conversation.
  • The company is much smaller than the incumbent alternatives, and while the MIT licence protects the code it does not protect the roadmap, so features on the hosted side may arrive slowly or change direction.

Kotlin Multiplatform

  • It shares logic, not UI, by default, so a team expecting a Flutter-style single UI codebase has to also adopt Compose Multiplatform, which is newer and less proven on iOS than on Android.
  • iOS interop relies on Kotlin/Native compiling to a framework consumed from Swift, and debugging across that boundary is more friction than debugging pure Swift or pure Kotlin.
  • Because logic-sharing is the whole premise, teams still need genuine iOS and Android UI expertise on staff; it does not reduce the native skills bar the way a full cross-platform UI framework aims to.
  • Build times and tooling maturity for multiplatform Gradle projects lag behind single-platform Kotlin or Swift projects, and multiplatform-specific build errors are less well documented.
  • JetBrains funds it as part of the broader Kotlin investment, so its roadmap priority competes internally with IntelliJ, Android Studio and other JetBrains commitments rather than having dedicated headcount the way Flutter has at Google.

Pricing, plan by plan

Formance

Free
  • Open SourceFree
    • MIT licensed core ledger
    • Numscript transaction DSL
    • Multi-currency tracking
  • Enterprise$undefined/year
    • Managed or private deployment
    • Payments connectivity and reconciliation
    • Support with response commitments

Kotlin Multiplatform

Free
  • Kotlin MultiplatformFree
    • Apache 2.0 licensed, unlimited apps
    • IDE tooling in the free Android Studio and free-tier IntelliJ IDEA Community
    • No paid Kotlin Multiplatform edition exists

Which should you pick?

Choose Formance if

  • You need double-entry ledger.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Web, API.
  • You also want numscript transaction dsl.
Formance review

Choose Kotlin Multiplatform if

  • You need shared kotlin logic.
  • You want to start without paying.
  • You work on iOS, Android, Windows, macOS, Linux, Web.
  • You also want native ui retained.
Kotlin Multiplatform review

Questions people ask

Is Formance or Kotlin Multiplatform better?
Neither clearly leads. Formance starts at Free and Kotlin Multiplatform at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Formance or Kotlin Multiplatform?
Formance starts at Free and Kotlin Multiplatform at Free.
Does Formance or Kotlin Multiplatform run on more platforms?
Formance runs on Linux, Docker, Kubernetes, Web, API. Kotlin Multiplatform runs on iOS, Android, Windows, macOS, Linux, Web.
Can I use Formance for free?
Both have a free tier, so you can try either at no cost before committing.
What is Formance best used for?
Formance is most often used for a marketplace splitting a single customer payment between seller, platform fee and tax that needs the split to be atomic and auditable, a fintech whose homegrown balances table produced numbers finance could not reconcile and now needs proper double-entry before an audit, a payments team that wants one normalised model across several psps so reconciliation is not written separately for each, a company that wants its ledger under a licence it can keep running even if the vendor disappears. Of those, a marketplace splitting a single customer payment between seller, platform fee and tax that needs the split to be atomic and auditable and a fintech whose homegrown balances table produced numbers finance could not reconcile and now needs proper double-entry before an audit are not what Kotlin Multiplatform is typically brought in for.
What can Formance do that Kotlin Multiplatform cannot?
Formance covers Double-entry ledger, Numscript transaction DSL, Multi-currency, Payments connectivity. Kotlin Multiplatform covers Shared Kotlin logic, Native UI retained, Compose Multiplatform (optional), IDE tooling.

Answered from the vendors’ own pages

Formance: Is Formance really open source?

Yes. The core ledger is MIT licensed with full source access and no deployment restrictions.

Kotlin Multiplatform: Does Kotlin Multiplatform replace my native UI code?

Not by default. It shares business logic and data layers; UI stays native per platform unless you separately adopt Compose Multiplatform.

Formance: Does Formance move money?

No. It records and orchestrates movements; the actual payments happen at a PSP or bank you connect.

Kotlin Multiplatform: Is there a paid version?

No. It is Apache 2.0 licensed and free, funded by JetBrains as part of the Kotlin project.

Formance: What does the enterprise version cost?

Not published. It is an annual subscription quoted per customer.

Kotlin Multiplatform: Do I need Compose Multiplatform to use it?

No, they are separate. You can share only logic and keep fully native UI on each platform indefinitely.

Formance: Do I have to use Numscript?

Yes for anything beyond the simplest transfers. It is how multi-party transactions are expressed atomically.

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