// GLOSSARY -- PAYMENTS & FINTECH

What is a Virtual Card?

1 min read Updated

A virtual card is a programmatically generated payment card number with configurable spending limits, merchant restrictions, and expiration — used for online payments without a physical card, often for employee expense management and subscription control.

WHY IT MATTERS

Virtual cards (from providers like Brex, Ramp, Mercury, Stripe Issuing) transformed corporate expense management. Instead of giving employees a corporate card, you issue per-vendor virtual cards with specific limits: $500/month for AWS, $100/month for Slack, expiring in 30 days.

This model maps directly to agent spending. Instead of giving an agent unrestricted wallet access, you create per-purpose spending allocations with specific limits — conceptually identical to virtual cards but implemented on-chain.

The parallel is strong enough that 'virtual card for AI agents' is a useful mental model for PolicyLayer-style spending controls. Each agent gets a defined spending allocation with limits, restrictions, and automatic expiration.

HOW POLICYLAYER USES THIS

PolicyLayer is like a virtual card system for AI agents — programmable spending limits, merchant (recipient) restrictions, category controls, and automatic expiration, all enforced on-chain for agent crypto transactions.

FREQUENTLY ASKED QUESTIONS

How are virtual cards different from PolicyLayer?
Virtual cards work on traditional card networks (Visa/Mastercard). PolicyLayer provides the same concept for on-chain crypto transactions. The control model is similar: per-entity spending limits with restrictions.
Can agents use actual virtual cards?
Yes, for traditional payment scenarios. Services like Stripe Issuing can generate cards programmatically for agents to use. For crypto payments, on-chain policy enforcement (like PolicyLayer) provides equivalent controls.
What makes virtual cards good for agents?
Programmability (create via API), isolation (each card is independent), limits (built-in spending caps), and disposability (create, use, destroy). These properties all apply to on-chain agent spending controls.

FURTHER READING

Enforce policies on every tool call

Intercept is the open-source MCP proxy that enforces YAML policies on AI agent tool calls. No code changes needed.

npx -y @policylayer/intercept
github.com/policylayer/intercept →
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