Softwr

Accounting · head to head

Mercury vs Sardine

Mercury logo

Mercury

Accounting

Banking for startups

From
Free
Rated
-
Full reviewWebsite
Sardine logo

Sardine

Cybersecurity

Device intelligence and behaviour biometrics for fraud and compliance

From
On request
Rated
-
Full reviewWebsite

The short version

  • Only Mercury has a free tier, so it costs nothing to try first.
  • Each has a real cost: Mercury treasury access requires a $250,000 balance held with Mercury; Sardine signal quality depends on the SDK being embedded in your own web and mobile clients, so fraud improvements become dependent on your app release cycle and any coverage gap is a blind spot.
  • They diverge on capability: Mercury covers Business checking, Sardine covers Device intelligence.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Mercury and Sardine actually diverge.

Attributes where Mercury and Sardine differ
AttributeMercurySardine
Starting priceFreeOn request
Pricing modelfreemiumquote
Free tierYesNo
CategoryAccountingCybersecurity
Founded2019Unknown

Identical on both: platforms (Web, Ios, Android), 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 Mercury

  • Business checking
  • Savings accounts
  • Virtual cards
  • Team management
  • API access
  • QuickBooks
  • Xero
  • Stripe

Only in Sardine

  • Device intelligence
  • Behaviour biometrics
  • Scam detection
  • Onboarding risk scoring
  • AML transaction monitoring
  • Dispute and chargeback handling
  • Rules editor

What people use each for

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

Mercury

  • Business banking and payments for startupsnot Sardine
  • Managing treasury, invoicing and corporate cards from one accountnot Sardine

Sardine

  • A neobank losing money to authorised push payment scams where the customer genuinely approved the transfernot Mercury
  • A crypto exchange trying to detect accounts being operated by remote access rather than by their ownernot Mercury
  • A fintech seeing synthetic identity signups that pass document verification but share device characteristicsnot Mercury
  • A lender wanting first party fraud signals at application time that a credit bureau file does not containnot Mercury

Where each one falls short

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

Mercury

  • Treasury access requires a $250,000 balance held with Mercury
  • Non USD international wires carry a 1% conversion fee
  • Choosing OUR wire coding, which covers intermediary bank charges, costs $15 per wire
  • ACH invoicing is $1 per transaction on Mercury Plus and only free on the $299 a month Pro plan
  • Advanced and recurring invoicing require Mercury Plus at $29.90 a month

Sardine

  • Signal quality depends on the SDK being embedded in your own web and mobile clients, so fraud improvements become dependent on your app release cycle and any coverage gap is a blind spot.
  • Behavioural and device telemetry collection needs a documented lawful basis under GDPR, and EU privacy reviews frequently delay rollouts that were scoped as engineering work.
  • Pricing is per session or per active user, so a consumer product with many low value sessions pays in proportion to traffic rather than to fraud exposure.
  • As a younger private company it lacks the enforcement-tested audit history that a bank examiner expects, which makes it a harder sell inside a regulated bank than inside a fintech.
  • It is strongest on session-time signals and weaker as a system of record for long horizon AML typologies, so larger institutions end up running it alongside a traditional monitoring platform rather than instead of one.

Pricing, plan by plan

Mercury

Free
  • Mercury (Free)Free
    • ACH payments
    • Domestic wires
    • Real-time payments
  • Mercury Plus$29.9/month
    • Invoice ACH debits
    • Recurring invoices
    • Invoicing API (500/month)
  • Mercury Pro$299/month
    • All Plus features
    • Relationship manager
    • Free ACH invoice debits

Sardine

On request
  • Sardine$undefined/year
    • Priced per user session or per monthly active user
    • Annual contract with volume commitment
    • SDK for web, iOS and Android

Which should you pick?

Choose Mercury if

  • You need business checking.
  • You want to start without paying.
  • You work on Web, Ios, Android.
  • You also want savings accounts.
Mercury review

Choose Sardine if

  • You need device intelligence.
  • You work on Web, iOS, Android.
  • You also want behaviour biometrics.
Sardine review

Questions people ask

Is Mercury or Sardine better?
Neither clearly leads. Mercury starts at Free and Sardine at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Mercury or Sardine?
Mercury has a free tier; the other does not. Paid plans start at Free for Mercury and On request for Sardine.
Does Mercury or Sardine run on more platforms?
Mercury runs on Web, Ios, Android. Sardine runs on Web, iOS, Android.
Can I use Mercury for free?
Yes. Mercury has a free tier, so you can try it without paying. Sardine starts at On request.
What is Mercury best used for?
Mercury is most often used for business banking and payments for startups, managing treasury, invoicing and corporate cards from one account. Of those, business banking and payments for startups and managing treasury, invoicing and corporate cards from one account are not what Sardine is typically brought in for.
What can Mercury do that Sardine cannot?
Mercury covers Business checking, Savings accounts, Virtual cards, Team management. Sardine covers Device intelligence, Behaviour biometrics, Scam detection, Onboarding risk scoring.

Answered from the vendors’ own pages

Mercury: Is Mercury business banking free?

Mercury's base banking tier is free and includes ACH payments, domestic wire transfers, real-time payments, Bill Pay, and QuickBooks/Xero automations at no monthly cost.

Source
Sardine: Does Sardine do document verification?

It focuses on device, behavioural and transaction signals, and integrates identity verification providers rather than being one. Treat it as complementary to a KYC vendor.

Mercury: What does Mercury Plus add beyond the free tier?

Mercury Plus costs $29.90 per month and adds invoice ACH debits, recurring invoice capabilities, invoicing API with 500 calls per month, unlimited 1099 filings, and access to partner benefits.

Source
Sardine: What does it need from us to work?

An SDK in your web and mobile applications plus transaction feeds. Without the client side collector you lose the signals that differentiate it.

Mercury: Does Mercury charge monthly account fees?

No, Mercury states there are no minimum account balance requirements, overdraft fees, required monthly fees, or account opening fees. The free tier includes essential business banking, with paid tiers available for additional features.

Source
Sardine: Is pricing published?

No. It is quoted, typically per session or per monthly active user with an annual volume commitment.

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