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Personal Finance · head to head

Firefly III vs Monzo

Firefly III logo

Firefly III

Personal Finance

Free, open source, self-hosted personal finance manager with double-entry style accounting

From
Free
Rated
-
Full reviewWebsite
Monzo logo

Monzo

Personal Finance

UK-licensed digital bank with FSCS-protected deposits and no foreign currency card fees

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Firefly III there is no official managed hosting, so a non-technical user has no easy on-ramp the way Actual Budget offers with its paid hosted sync.; Monzo monzo is UK-focused, so customers wanting deep multi-currency holding, broad international transfers or in-app investing will find its feature set narrower than Revolut.
  • They diverge on capability: Firefly III covers Double-entry style ledger, Monzo covers FSCS-protected deposits.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Firefly III and Monzo actually diverge.

Attributes where Firefly III and Monzo differ
AttributeFirefly IIIMonzo
Pricing modelOpen source, no licence feeFree core current account; paid Plus and Premium tiers add features
PlatformsWeb, Linux, DockeriOS, Android, Web

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Personal Finance).

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 Firefly III

  • Double-entry style ledger
  • Multi-currency accounts
  • Bill and subscription tracking
  • Rule engine
  • Reports and charts
  • API access

Only in Monzo

  • FSCS-protected deposits
  • Fee-free foreign spending
  • Savings Pots
  • Joint and shared accounts
  • Instant spending notifications
  • Overdrafts and loans

What people use each for

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

Firefly III

  • A self-hoster already running a home server or NAS who wants their financial ledger on the same infrastructurenot Monzo
  • Someone who wants double-entry style accuracy rather than simple envelope budgetingnot Monzo
  • A privacy-focused user who refuses to put financial data on any third-party server, hosted or otherwisenot Monzo
  • A developer who wants API access to build custom bank import scripts for accounts with no standard connectornot Monzo

Monzo

  • A UK resident wanting a free current account with statutory FSCS deposit protection rather than e-money safeguardingnot Firefly III
  • A frequent traveller wanting free foreign currency card spending on a UK-regulated accountnot Firefly III
  • A household wanting a joint account with shared budgeting and spending visibilitynot Firefly III
  • Someone building savings using automated Pots with partner-bank interest rather than a separate savings accountnot Firefly III

Where each one falls short

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

Firefly III

  • There is no official managed hosting, so a non-technical user has no easy on-ramp the way Actual Budget offers with its paid hosted sync.
  • The double-entry-influenced model is less intuitive for newcomers than simple envelope budgeting, and the learning curve is real.
  • Automatic bank sync depends on the community-run importer and third-party connectors, and coverage and reliability vary a lot by bank and country.
  • Mobile access is via a web interface rather than a polished native app, which is a step behind Actual Budget or Lunch Money on phones.
  • Because there is no company behind it, security patching and feature development depend entirely on volunteer maintainer time.

Monzo

  • Monzo is UK-focused, so customers wanting deep multi-currency holding, broad international transfers or in-app investing will find its feature set narrower than Revolut.
  • Overdraft and loan products carry interest charges based on individually assessed rates, and like any consumer credit product the cost varies by risk profile rather than being a flat, predictable fee.
  • Free ATM withdrawals abroad are capped at a monthly limit on the free tier, after which a fee applies, so heavy cash users abroad may find the free tier insufficient.
  • As an app-first bank with very limited physical presence, customers who prefer in-person branch banking or need to deposit cash regularly will find it inconvenient compared with a traditional high street bank.
  • Some paid-tier perks, such as travel insurance bundled into Premium, require reading policy terms carefully, since bundled insurance products can have narrower cover than a standalone policy bought separately.

Pricing, plan by plan

Firefly III

Free
  • Firefly IIIFree
    • Full functionality, self-hosted
    • No usage limits
    • Community support, donations accepted

Monzo

Free
  • Monzo (free)Free
    • Free current account with FSCS-protected deposits
    • Fee-free foreign currency card spending
    • Free ATM withdrawals abroad up to a monthly limit
  • Monzo Plus$5/month
    • Higher fee-free overseas ATM withdrawal limit
    • Custom card colours and virtual cards
    • Savings and budgeting extras
  • Monzo Premium$15/month
    • Travel and phone insurance included
    • Metal card
    • Airport lounge access on some plans

Which should you pick?

Choose Firefly III if

  • You need double-entry style ledger.
  • You want to start without paying.
  • You work on Web, Linux, Docker.
  • You also want multi-currency accounts.
Firefly III review

Choose Monzo if

  • You need fscs-protected deposits.
  • You want to start without paying.
  • You work on iOS, Android, Web.
  • You also want fee-free foreign spending.
Monzo review

Questions people ask

Is Firefly III or Monzo better?
Neither clearly leads. Firefly III starts at Free and Monzo at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Firefly III or Monzo?
Firefly III starts at Free and Monzo at Free.
Does Firefly III or Monzo run on more platforms?
Firefly III runs on Web, Linux, Docker. Monzo runs on iOS, Android, Web.
Can I use Firefly III for free?
Both have a free tier, so you can try either at no cost before committing.
What is Firefly III best used for?
Firefly III is most often used for a self-hoster already running a home server or nas who wants their financial ledger on the same infrastructure, someone who wants double-entry style accuracy rather than simple envelope budgeting, a privacy-focused user who refuses to put financial data on any third-party server, hosted or otherwise, a developer who wants api access to build custom bank import scripts for accounts with no standard connector. Of those, a self-hoster already running a home server or nas who wants their financial ledger on the same infrastructure and someone who wants double-entry style accuracy rather than simple envelope budgeting are not what Monzo is typically brought in for.
What can Firefly III do that Monzo cannot?
Firefly III covers Double-entry style ledger, Multi-currency accounts, Bill and subscription tracking, Rule engine. Monzo covers FSCS-protected deposits, Fee-free foreign spending, Savings Pots, Joint and shared accounts.

Answered from the vendors’ own pages

Firefly III: Can I pay someone to host Firefly III for me?

Not through the core project; some third-party providers sell Firefly III hosting independently, but there is no official managed service.

Monzo: Is Monzo a real bank?

Yes, Monzo Bank Limited holds a full UK banking licence and is regulated by the FCA and PRA, the same framework as traditional UK banks.

Firefly III: Does it support multiple currencies?

Yes, natively, including accounts and transactions in different currencies.

Monzo: Are my savings protected if Monzo fails?

Eligible deposits are covered by the Financial Services Compensation Scheme up to 85,000 pounds per eligible person, the same statutory protection as other UK banks.

Firefly III: Is it really free with no paid tier?

Yes, the software is free and open source under the AGPL; the project accepts donations but sells nothing.

Monzo: Does Monzo charge for spending abroad?

No card fee applies for purchases abroad at the interbank exchange rate; free ATM withdrawals abroad are capped at a monthly limit before a fee applies.

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