RuleIQ — AML/KYC Essentials for Fintechs

The Build vs Buy Decision for Transaction Monitoring

Every fintech eventually faces this question: should we build our own transaction monitoring system (TMS) or buy one from a vendor? The answer depends on your stage, resources, regulatory expectations, and risk appetite. Get this wrong and you'll either overspend on a system you don't need yet, or underinvest and face regulatory action.

When Building Makes Sense

Building your own TMS can be the right choice if:

You have a unique data model. If your product generates transaction data that doesn't fit neatly into traditional banking patterns — for example, a crypto exchange or a B2B payments platform with complex invoice matching — off-the-shelf solutions may require so much customization that building is cheaper.
You have engineering resources to spare. A minimum viable TMS requires 2-3 senior engineers working for 3-6 months. You'll also need ongoing maintenance of roughly 0.5-1 FTE permanently.
You're at scale. Once you're processing more than 1 million transactions per month, vendor per-transaction pricing can become expensive. At 10M+ transactions/month, the economics often favor building.

Realistic cost estimate for building:

Initial development: $300,000-$600,000 (3-6 months, 2-3 engineers at $150K-$200K loaded cost)
Ongoing maintenance: $150,000-$250,000/year
Infrastructure: $2,000-$10,000/month depending on volume
Total Year 1: $500,000-$900,000

When Buying Makes Sense

For most early-stage fintechs (pre-Series B), buying is the right call. Here's why:

Speed to compliance. A vendor can have you live in 4-8 weeks. Building takes 3-6 months minimum — and regulators won't wait.
Regulatory credibility. Examiners recognize established vendors. Using Chainalysis or ComplyAdvantage signals seriousness in a way that a homegrown spreadsheet-based system does not.
Built-in rule libraries. Vendors ship with hundreds of pre-configured rules based on FinCEN guidance and industry best practices. You'd need a full-time BSA analyst to replicate that logic from scratch.
Automatic updates. When FinCEN issues new guidance or OFAC updates its SDN list, vendors push updates. With a homegrown system, that's on you.

Vendor Landscape: Key Players

Chainalysis (KYT - Know Your Transaction)

Best for: Crypto-native companies
Strengths: Deep blockchain analytics, wallet clustering, real-time transaction screening
Pricing: Starts around $50,000/year for smaller volumes; can exceed $500K for large exchanges
Consideration: If you're not in crypto, this isn't the right tool

ComplyAdvantage

Best for: Fintechs needing combined AML screening + transaction monitoring
Strengths: AI-powered risk detection, real-time adverse media screening, good API integration
Pricing: Typically $30,000-$150,000/year depending on volume and modules
Consideration: Strong for companies that need both KYC screening and transaction monitoring in one platform

Unit21

Best for: Fintechs that want a no-code rule builder with flexibility
Strengths: Highly configurable rules engine, case management, strong API-first design
Pricing: Starts around $3,000-$5,000/month for early-stage companies; scales with volume
Consideration: Good for teams that want to iterate on rules without engineering support

Sardine

Best for: Companies focused on fraud + AML convergence
Strengths: Device intelligence, behavioral biometrics, combines fraud and AML into one risk score
Pricing: Volume-based, typically starting at $2,000-$5,000/month
Consideration: Excellent if your biggest risk is fraud-driven money laundering (common in neobanks and payment apps)

Key Decision Factors Checklist

Transaction volume: Under 100K transactions/month? Buy. Over 5M/month? Evaluate building.
Engineering team size: Fewer than 20 engineers total? Don't divert resources to TMS. Buy.
Regulatory timeline: If you need to be compliant in under 3 months, buy.
Data complexity: Standard payment flows? Buy. Highly unique data (DeFi, complex derivatives)? Consider building.
Budget: Can you commit $50K+/year to a vendor? If not, start with a simpler tool and upgrade.
Integration requirements: Check that the vendor's API supports your tech stack. Request sandbox access before signing.

The Hybrid Approach

Many mature fintechs end up with a hybrid model: they use a vendor for standard rule-based monitoring and sanctions screening, then build custom analytics on top for their unique risk patterns. This gives you the compliance credibility of a recognized vendor plus the flexibility of custom detection logic. Start with buy, then selectively build as you identify gaps that the vendor can't address.