Softwr

Accounting · head to head

Lago vs Medius

Lago logo

Lago

Accounting

Open-source billing infrastructure for usage-based models

From
Free
Rated
-
Full reviewWebsite
Medius logo

Medius

Accounting

Accounts payable automation and supplier payments for mid-market finance teams, Marlin Equity owned

From
On request
Rated
-
Full reviewWebsite

The short version

  • Only Lago has a free tier, so it costs nothing to try first.
  • Each has a real cost: Lago free tier limited to 10,000 entities per month with 5M event cap; Medius the sourcing, contract and procurement modules are considerably less developed than the AP core, so buying Medius as a full source-to-pay suite means accepting weak upstream tooling.
  • They diverge on capability: Lago covers Real-time usage metering, Medius covers Invoice capture and coding.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Lago and Medius actually diverge.

Attributes where Lago and Medius differ
AttributeLagoMedius
Starting priceFreeOn request
Pricing modelFreemium with optional paid tiersquote
Free tierYesNo
PlatformsWeb, Cloud, Self-hosted, On-premise, VPCWeb, iOS, Android

Identical on both: 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 Lago

  • Real-time usage metering
  • Multiple pricing models
  • Automated invoicing
  • Prepaid credits
  • Entitlements
  • Multi-currency support
  • Payment orchestration
  • Revenue analytics

Only in Medius

  • Invoice capture and coding
  • Matching and exception handling
  • Fraud and anomaly detection
  • Supplier payments
  • Approval workflow
  • ERP integration

What people use each for

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

Lago

  • Building usage-based billing for high-volume APIs and infrastructurenot Medius
  • Implementing metered billing for AI and tokenized servicesnot Medius
  • Creating subscription and hybrid pricing modelsnot Medius
  • Managing multi-currency billing for global companiesnot Medius
  • Maintaining billing infrastructure without vendor lock-innot Medius

Medius

  • A mid-market finance team where most spend arrives as an invoice with no purchase order to match againstnot Lago
  • A group with several legal entities on different ERPs that wants one AP process across all of themnot Lago
  • Reducing invoice fraud exposure with automated detection of supplier bank detail changesnot Lago
  • Replacing a scanning bureau and a shared AP inbox with automated capture and exception-based reviewnot Lago

Where each one falls short

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

Lago

  • Free tier limited to 10,000 entities per month with 5M event cap
  • No specific pricing published for Pro annual plan or Scale plan
  • Self-hosted and on-premise deployments require engineering resources
  • Community support only on free tier
  • Scale plan requires annual contracts and sales engagement

Medius

  • The sourcing, contract and procurement modules are considerably less developed than the AP core, so buying Medius as a full source-to-pay suite means accepting weak upstream tooling.
  • Pricing is quote-only and driven by invoice volume, so a business with many low-value invoices pays disproportionately relative to the spend being controlled.
  • Payments are billed on transaction volume separately from the AP subscription, which is easy to omit from a cost comparison against a licence-only AP tool.
  • Private equity ownership since 2017 has produced an acquisition-driven product line, so payments and adjacent capability come from bought-in technology rather than the original platform.
  • ERP integration depth varies sharply by system, and organisations on less common or heavily customised ERPs face integration work that lengthens the implementation.

Pricing, plan by plan

Lago

Free
  • Build (Free)Free
    • 10,000 managed entities per month
    • 5M usage events per month
    • 1K events per second rate limit
  • Pro$399/month
    • 10,000 entities included (graduated pricing to 100K)
    • 25M usage events included (to 500M with graduated rates)
    • 10K events per second (upgradeable to 100K)
  • Scale$null/custom
    • Custom entity and event volumes
    • 50K events per second (upgradeable to 100K)
    • RBAC and SSO (SAML)

Medius

On request
  • Medius AP Automation$undefined/year
    • Two packaged AP automation tiers
    • Priced by invoice volume and entity count
    • Sourcing, contracts and procurement modules sold separately

Which should you pick?

Choose Lago if

  • You need real-time usage metering.
  • You want to start without paying.
  • You work on Web, Cloud, Self-hosted, On-premise, VPC.
  • You also want multiple pricing models.
Lago review

Choose Medius if

  • You need invoice capture and coding.
  • You work on Web, iOS, Android.
  • You also want matching and exception handling.
Medius review

Questions people ask

Is Lago or Medius better?
Neither clearly leads. Lago starts at Free and Medius at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Lago or Medius?
Lago has a free tier; the other does not. Paid plans start at Free for Lago and On request for Medius.
Does Lago or Medius run on more platforms?
Lago runs on Web, Cloud, Self-hosted, On-premise, VPC. Medius runs on Web, iOS, Android.
Can I use Lago for free?
Yes. Lago has a free tier, so you can try it without paying. Medius starts at On request.
What is Lago best used for?
Lago is most often used for building usage-based billing for high-volume apis and infrastructure, implementing metered billing for ai and tokenized services, creating subscription and hybrid pricing models, managing multi-currency billing for global companies. Of those, building usage-based billing for high-volume apis and infrastructure and implementing metered billing for ai and tokenized services are not what Medius is typically brought in for.
What can Lago do that Medius cannot?
Lago covers Real-time usage metering, Multiple pricing models, Automated invoicing, Prepaid credits. Medius covers Invoice capture and coding, Matching and exception handling, Fraud and anomaly detection, Supplier payments.

Answered from the vendors’ own pages

Lago: Can I use Lago open-source for free?

Yes, Lago is open-source under the AGPLv3 license and can be self-hosted. The cloud-based Build plan is also free with limits of 10,000 entities and 5M events per month.

Source
Medius: Is Medius a procurement suite or an AP tool?

Primarily an AP automation platform with procurement modules attached. If sourcing is your main requirement, look elsewhere.

Lago: What payment providers does Lago integrate with?

Lago integrates with Stripe and Adyen for payment processing. It is not a payment processor itself but orchestrates payments through these providers.

Source
Medius: Who owns Medius?

Marlin Equity Partners, which acquired it in 2017 and has funded several bolt-on acquisitions since.

Lago: Does Lago support multiple currencies?

Yes, Lago supports multi-currency billing with automatic currency conversion for global businesses.

Source
Medius: How is it priced?

By quote, driven by invoice volume and entity count, with payments billed separately on transaction volume.

Medius: Does it replace our ERP?

No. It sits alongside the ERP and posts approved invoices into it.

Share

Related pages

More on Lago

More on Medius

Keep looking

Other head to heads