Revenue Leakage Glossary
Definitions for the terms you'll meet on the way to plugging your revenue leaks.
Revenue leakage operates at the intersection of finance, billing, and operations — a domain where the same idea has three names depending on who's talking. Auditors call it “revenue assurance.” Finance teams call it “ARR leakage.” Engineers call it a “billing bug.” All three are looking at the same dollars silently leaving the business.
This glossary defines 13 terms grouped into four areas: concept foundations (the big-picture vocabulary), billing & recovery (the operational machinery), customer metrics (the KPIs that surface leakage), and tools & operations (the function and the software). Each entry links back to the Revenue Leakage Pillar Guide for context on where the term fits in a detection or prevention workflow.
Concept Foundations 3 terms
Revenue Leakage
Revenue leakage is the unintentional loss of earned or expected revenue due to billing errors, pricing misconfigurations, failed payments, contract non-compliance, or operational process gaps.
Revenue Assurance
Revenue assurance (RA) is the practice of ensuring that all revenue earned by an organization is accurately captured, billed, collected, and reported — preventing revenue leakage throughout the revenue lifecycle.
ARR Leakage
ARR leakage is the difference between a SaaS company's expected Annual Recurring Revenue (based on active subscriptions and contracted rates) and the revenue actually collected, caused by billing errors, payment failures, and pricing gaps.
Billing & Recovery 4 terms
Dunning
Dunning is the systematic process of communicating with customers about failed payments and attempting to recover the revenue through automated retries, payment method updates, and escalation sequences.
Billing Reconciliation
Billing reconciliation is the process of comparing and verifying that the amounts billed to customers match the contracted terms, the services delivered, and the payments actually collected.
Failed Payment Recovery
Failed payment recovery is the process of detecting, retrying, and collecting subscription payments that initially fail due to expired cards, insufficient funds, bank declines, or processing errors.
Subscription Billing Errors
Subscription billing errors are inaccuracies in the recurring billing process that result in customers being charged incorrectly — either too much (compliance risk, refund liability) or too little (revenue leakage).
Customer Metrics 4 terms
Involuntary Churn
Involuntary churn is the loss of customers due to payment processing failures rather than a deliberate decision to cancel. It accounts for 20-40% of total churn in subscription businesses.
Churn Rate
Churn rate is the percentage of customers (customer churn) or revenue (revenue churn) lost during a given period, typically measured monthly or annually.
Net Revenue Retention (NRR)
Net Revenue Retention (NRR) measures the percentage of recurring revenue retained from existing customers over a period, accounting for upgrades, downgrades, and churn — but excluding new customer revenue.
Pricing Drift
Pricing drift is the gradual divergence between a company's intended pricing and the actual prices charged to customers, caused by manual errors, system misconfigurations, or accumulated exceptions.
Tools & Operations 2 terms
Revenue Operations (RevOps)
Revenue Operations (RevOps) is the strategic function that aligns sales, marketing, and customer success operations to drive predictable revenue growth through process optimization, data integration, and technology alignment.
Revenue Assurance Software
Revenue assurance software is a category of tools that automatically detect, quantify, and help recover revenue lost to billing errors, pricing discrepancies, contract non-compliance, and failed payment recovery gaps.