APIs · head to head
Basis Theory vs Medius
Basis Theory
APIs
Developer tokenisation platform that holds card and sensitive data inside a PCI Level 1 environment you do not operate
- From
- $995/month
- Rated
- -
Medius
Accounting
Accounts payable automation and supplier payments for mid-market finance teams, Marlin Equity owned
- From
- On request
- Rated
- -
The short version
- Each has a real cost: Basis Theory the Starter plan is 995 US dollars a month before any volume, which is a real floor for an early stage company and puts the product out of reach of teams tokenising a few thousand records.; 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: Basis Theory covers Tokenisation API, 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 Basis Theory and Medius actually diverge.
| Attribute | Basis Theory | Medius |
|---|---|---|
| Starting price | $995/month | On request |
| Pricing model | Per month by token volume | quote |
| Platforms | Web, iOS, Android, Linux | Web, iOS, Android |
| Category | APIs | Accounting |
Identical on both: free tier (No), 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 Basis Theory
- Tokenisation API
- Hosted elements
- Outbound proxy
- PCI attestation of compliance
- Processor portability
- Reactors
- Access controls and audit
- PII and PHI options
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.
Basis Theory
- A payments company that wants card on file without bringing its own infrastructure into PCI scope and paying for the assessment that followsnot Medius
- A merchant locked into a processor by that processor vault that wants to hold its own tokens and route to more than one acquirernot Medius
- A fintech collecting bank account and identity data that needs it isolated from its application database before an enterprise security reviewnot Medius
- A team that needs to send stored card data to a third party for a one-off integration without that data traversing its own serversnot Medius
Medius
- A mid-market finance team where most spend arrives as an invoice with no purchase order to match againstnot Basis Theory
- A group with several legal entities on different ERPs that wants one AP process across all of themnot Basis Theory
- Reducing invoice fraud exposure with automated detection of supplier bank detail changesnot Basis Theory
- Replacing a scanning bureau and a shared AP inbox with automated capture and exception-based reviewnot Basis Theory
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
Basis Theory
- The Starter plan is 995 US dollars a month before any volume, which is a real floor for an early stage company and puts the product out of reach of teams tokenising a few thousand records.
- Starter is limited to the US region, so a company with European data residency requirements is pushed into a quoted Scale or Enterprise agreement immediately.
- Log retention on Starter is 24 hours, which is well below what most security teams expect for a system holding cardholder data and forces an upgrade for reasons unrelated to volume.
- Migrating away means moving card data out of the vault, which requires processor and assessor involvement and is slow, so the portability argument that attracts buyers cuts against them at exit.
- An attestation of compliance covers the vendor environment, not your assessment; your assessor still decides what is in scope, and buyers occasionally discover their integration pattern pulled systems back into scope anyway.
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
Basis Theory
$995/month- Starter$995/month
- 20,000 tokens included
- Production PCI Level 1 environment
- US region only
- Scale$undefined/month
- Quoted
- Higher token volumes
- Additional regions
- Enterprise$undefined/month
- Quoted
- Additional compliance options for PII and PHI
- Responses for 95 percent of PCI SAQ D
Medius
On request- Medius AP Automation$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 Basis Theory if
- You need tokenisation api.
- You work on Web, iOS, Android, Linux.
- You also want hosted elements.
Choose Medius if
- You need invoice capture and coding.
- You work on Web, iOS, Android.
- You also want matching and exception handling.
Questions people ask
- Is Basis Theory or Medius better?
- Neither clearly leads. Basis Theory starts at $995/month and Medius at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, Basis Theory or Medius?
- Basis Theory starts at $995/month and Medius at On request.
- Does Basis Theory or Medius run on more platforms?
- Basis Theory runs on Web, iOS, Android, Linux. Medius runs on Web, iOS, Android.
- What is Basis Theory best used for?
- Basis Theory is most often used for a payments company that wants card on file without bringing its own infrastructure into pci scope and paying for the assessment that follows, a merchant locked into a processor by that processor vault that wants to hold its own tokens and route to more than one acquirer, a fintech collecting bank account and identity data that needs it isolated from its application database before an enterprise security review, a team that needs to send stored card data to a third party for a one-off integration without that data traversing its own servers. Of those, a payments company that wants card on file without bringing its own infrastructure into pci scope and paying for the assessment that follows and a merchant locked into a processor by that processor vault that wants to hold its own tokens and route to more than one acquirer are not what Medius is typically brought in for.
- What can Basis Theory do that Medius cannot?
- Basis Theory covers Tokenisation API, Hosted elements, Outbound proxy, PCI attestation of compliance. Medius covers Invoice capture and coding, Matching and exception handling, Fraud and anomaly detection, Supplier payments.
Answered from the vendors’ own pages
Basis Theory: Does this make us PCI compliant?
It removes cardholder data from your systems and gives you an AOC plus documented responses for most of a SAQ D. Your assessor still determines your scope, and a careless integration can pull systems back in.
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.
Basis Theory: What does it cost to start?
995 US dollars a month on Starter, including 20,000 tokens, a production PCI Level 1 environment and US hosting. Higher tiers are quoted.
Medius: Who owns Medius?
Marlin Equity Partners, which acquired it in 2017 and has funded several bolt-on acquisitions since.
Basis Theory: Can we switch payment processors without re-collecting cards?
Yes, that is the main non-compliance reason to buy it. You hold the tokens and detokenise into whichever processor you route to.
Medius: How is it priced?
By quote, driven by invoice volume and entity count, with payments billed separately on transaction volume.
Basis Theory: Is data stored outside the United States?
Not on Starter, which is US only. Other regions require a Scale or Enterprise agreement.
Medius: Does it replace our ERP?
No. It sits alongside the ERP and posts approved invoices into it.
Related pages
More on Basis Theory
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- Medius vs Trustly
- Medius vs Vodeno
- Medius vs TrueLayer
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- Medius vs Ottimate
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- Medius vs Paddle
- Medius vs Modern Treasury
- Medius vs Dodo Payments
- Medius vs Melio
- Medius vs Adyen
- Medius vs Fortnox
- Medius vs FreeAgent
- Medius vs freee
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- Medius vs insightsoftware
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