Agentifact assessment — independently scored, not sponsored. Last verified Mar 6, 2026.

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Teller

US bank account API with instant live connections to 7,000+ institutions; free tier for indie developers up to 100 connections

Visit TellerVerified · March 6, 2026

✓ Our Verdict

Viable option — review the tradeoffs

Use Case

You need to let users securely link US bank accounts and access live data like balances, transactions, and routing numbers without building Plaid-like infrastructure.

SolutionTeller provides instant connections to 7,000+ US banks via REST API and client-side Teller Connect UI, delivering account details, real-time balances, categorized transactions, and verification.

SetupSign up for free tier (up to 100 connections), get application ID and mTLS client certificate from dashboard, embed Teller Connect script with products like 'verify', 'balance', 'transactions', then use access tokens for API calls.

Instant connections for most banks work smoothly with reliable data enrichment; some institutions lack full features (check 'links' object), initial transaction calls may timeout on high-volume accounts, sandbox is free for testing.

Integration ease

Use Case

You're an indie developer validating bank account ownership and ACH details for payouts or transfers in your MVP.

SolutionUse Teller's 'verify' and 'verify.instant' products to get masked account numbers, ACH/wire routing instantly post-enrollment.

SetupConfigure Teller Connect with 'verify.instant' product, handle onSuccess callback for accessToken, fetch /accounts/{id}/details via mTLS-auth'd API.

Free tier covers 100 connections perfectly for indies; instant verification succeeds for supported banks but falls back to micro-deposits for others; data accurate but coverage varies by institution.

Cost efficiency

Limitation — major

US-Only Coverage

Connects exclusively to US institutions (7,000+ banks); no international support. Check 'links' object per account—incomplete for some banks on balances/transactions.

Prerequisite

mTLS Certificate Setup

Required for all end-user data API calls to mutually authenticate; HTTP Basic Auth insufficient. Generate via dashboard—non-trivial for beginners.

Caution

Free Tier Connection Limit

Up to 100 active connections only; exceeding requires paid plan. Monitor enrollments to avoid surprise cutoffs—dashboard shows usage.

Trust Breakdown

70

Trust scoreSolid

AGENT

Autonomous workflow delegation

TRUST

Transparency & verification

INTEROP

Protocol compatibility breadth

SECURITY

Security controls & audit trail

DOCS

Documentation completeness

How these scores are calculated →

What It Actually Does

In Plain English

Teller lets apps connect to users' US bank accounts to fetch real-time balances, transaction history, and account details from thousands of institutions.[1][3][5] It also supports sending instant Zelle payments between accounts.[2]

US bank account API with instant live connections to 7,000+ institutions; free tier for indie developers up to 100 connections.

Fit Assessment

Best for

✓banking-api
✓payment-processing
✓account-enrollment

70

Teller

Solid · 70/100

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Score Breakdown

AGENT

Autonomous workflow delegation

TRUST

Transparency & verification

INTEROP

Protocol compatibility breadth

SECURITY

Security controls & audit trail

DOCS

Documentation completeness

Protocol Support

MCP—

A2A—

A2H—

REST API✓

Agent-callable—

Capabilities

Transaction capable✓

ACP support—

Audit trace—

Governance

rate-limiting
permission-scoping

Pricing

Paid

Paid API service

Workflow Fit

banking-apipayment-processingaccount-enrollment

Related Concepts

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