Sardine vs Unit21

Sardine is the better fit for fintechs that want onboarding, fraud, and AML from one vendor, with device intelligence and ten ready-made risk agents; Unit21 is the better fit when AML monitoring, case management, and direct FinCEN filing are the center of the program and KYC comes from a partner. Runtime is the AI agent harness for payment and fintech teams, and it works the cases either one raises across payment ops, finance, and support.

Both sell fraud and AML with AI agents to fintechs, crypto companies, and sponsor banks, so they often meet in the same evaluation. The difference is where each one starts.

Sardine vs Unit21 at a glance

Sardine calls itself an agentic financial crime platform. It covers onboarding (KYC, KYB, credit underwriting), fraud (payments, card issuing, merchant monitoring, account takeover, bots), and AML (transaction monitoring, sanctions screening, customer risk rating, case management, sponsor bank monitoring). It sells ten AI agents and runs Sonar, a consortium that shares risk signals across members. It was named a Leader in the Forrester Wave for financial crime management in Q3 2026. Customers include FIS, Nubank, Gusto, and Deel.

Unit21 calls itself AI risk infrastructure for fraud and AML. It covers real-time monitoring, AML transaction monitoring, sanctions and payment screening, customer risk rating, a fraud consortium, device intelligence, case management, and regulatory filing, with SARs and CTRs filed directly to FinCEN and STRs to FINTRAC. Customers include Chime, Brex, Green Dot Bank, Crypto.com, and Intuit.

Product scope

Sardine. Wider at the front of the customer lifecycle. Identity checks at signup, device and behavioral signals, payment fraud scoring, and the AML program all live on one platform. That suits a fintech that wants fewer vendors and one risk view from onboarding onward.

Unit21. Deeper in the operations of an AML program. It does not offer a native KYC product and connects to identity vendors such as Persona, Socure, and Middesk instead. Its strength is the path from alert to case to filing, plus real-time rules that deny, escalate, or allow in milliseconds.

AI agents

Sardine. Ten agents: OSINT Search, Data Analyst, Rule Assistant, Transaction Monitoring, Business Due Diligence, Doc KYC, PEP Screening, Graph Analyst, Sanctions Screening, and SAR Generation. At its Series C, Sardine reported its KYC agent auto-resolving 88% of onboarding edge cases.

Unit21. The Detection Agent works alerts and learns from outcomes to reduce false positives, and the Investigation Agent summarizes risk, writes narratives, and surfaces linked entities. Build Your Own Agent and the July 2026 Agentic Task Builder let teams define custom tasks in plain English. Unit21 says more than 100 customers run its agents in production, and its agents do not close cases or file without a person.

Data and filing

Sardine. Device intelligence and behavioral biometrics are central, with Sonar adding signals from member companies. The SAR Generation agent drafts filings inside Sardine's case flow.

Unit21. Its fraud consortium covers more than 100 million US adults, per Unit21. Filing is a core product: direct FinCEN SAR and CTR e-filing with BSA ID tracking, FINTRAC STRs, and goAML exports. It also ingests from bank cores like Fiserv and Jack Henry and from data warehouses.

Pricing

Neither Sardine nor Unit21 publishes pricing. Both are sold through sales.

Where Runtime enters the picture

Sardine and Unit21 both decide and document risk well, and both stop at the compliance team's edge. A flagged card program customer is a good example. The alert opens in Sardine or Unit21, but the analyst also needs the processor's authorization history, the ledger balance, and the customer's open tickets. Once a decision is made, payment ops freezes the card or holds a payout, finance books the reserve, support writes to the customer, and someone answers the sponsor bank's RFI. Each team works the same customer in a different tool.

Runtime is the AI agent harness for payment and fintech teams. Agents read the case through Sardine's or Unit21's API, pull the data neither tool holds, draft the decision and every follow-up action, and wait for a person before a payout is held, a reserve applied, or a reply sent to the sponsor bank. Your risk platform stays the system of record for detection and filing.

• No single vendor to depend on. Agents run in your AWS, GCP, or Azure account or fully self-hosted, on your choice of sandbox provider with fallbacks, using Claude, GPT, Gemini, or open-weight models, with harness routing across Claude Code, Codex, and OpenCode.
• Guardrails you set. Read-only by default, approvals before money moves, RBAC, masked credentials, SSNs and card numbers stripped from prompts and logs, every run recorded for your examiner.
• Built for teams. Risk, compliance, payment ops, finance, and support share agents, templates, and one memory of every case.
• An engineer, not an account executive. A forward-deployed AI engineer with a payments background from Hulu's payments team at Disney, Finix, Modern Treasury, or BlackRock builds the first agents with your team.

Describe the jobConnect your tools, even legacy onesKeep a human in the loopNo single vendor to depend onOne memory across teamsEvery run is stored

[::]New agent

Create a banking ops agent that handles RFIs, hold-harmless requests, and returns of funds from our partner bank, verifies against our ledger, and drafts replies for my approval.

Describe the agent you want

Agent ready

bank-ops-agent

Tools picked from your prompt

EmailLedgerSFTPMastercard

Which should you choose

• Choose Sardine if you want onboarding, fraud, and AML from one vendor, with device intelligence, consortium data, and ten ready-made risk agents.
• Choose Unit21 if AML monitoring, real-time rules, case management, and direct FinCEN filing are the core of the job, and you already have a KYC vendor.
• Choose Runtime if your fraud and AML cases spill into payment ops, finance, and support, and you want agents in your cloud with approvals before money moves. Runtime runs alongside either one.

Frequently asked questions

What is the difference between Sardine and Unit21?

Sardine covers onboarding (KYC and KYB), fraud, and AML on one platform, with device intelligence, behavioral biometrics, and the Sonar consortium. Unit21 focuses on fraud and AML operations: real-time and AML monitoring, screening, case management, and direct SAR and CTR filing with FinCEN, with identity checks coming from partners.

Is Sardine or Unit21 better for a sponsor bank program?

Both serve sponsor banks and the fintechs on them. Sardine lists sponsor bank monitoring in its AML product. Unit21 names sponsor banks among its customers, such as Green Dot Bank and Sunrise Banks, and files directly with FinCEN. The choice usually turns on whether you also want onboarding and device-level fraud from the same vendor.

Do Sardine and Unit21 have AI agents?

Yes. Sardine lists ten agents, including Transaction Monitoring, Sanctions Screening, Graph Analyst, and SAR Generation. Unit21 has a Detection Agent and an Investigation Agent, plus Build Your Own Agent and an Agentic Task Builder for custom investigation tasks.

How much do Sardine and Unit21 cost?

Neither publishes pricing. Both are sold through sales.

Where does Runtime fit next to Sardine or Unit21?

Runtime is the AI agent harness for payment and fintech teams. Sardine or Unit21 detects and opens the case; Runtime agents investigate across the ledger, processor, bank files, and support tickets, draft the actions for payment ops and finance, and wait for a person before anything moves money.