Glossary term

Backlog

Backlog is the value of contracted or ordered work that a company has not yet delivered, fulfilled, or recognized as revenue.

Updated

May 22, 2026

Read time

3 min read

What Is Backlog?

Backlog is the value of contracted or ordered work that a company has not yet delivered, fulfilled, or recognized as revenue. It represents business already won but not yet completed. The term is common in construction, aerospace, defense, industrial equipment, software, consulting, and other project or contract-based businesses.

Backlog can be a useful signal of future revenue visibility. A company with a large backlog may have work lined up for future periods. But backlog is not the same as revenue, cash, profit, or guaranteed performance. The quality of the backlog matters.

Key Takeaways

  • Backlog measures contracted or ordered work that remains to be fulfilled.
  • It can indicate future revenue visibility, capacity needs, and customer demand.
  • Backlog definitions vary by industry and company.
  • A large backlog can be valuable, but only if it converts into profitable revenue and cash.
  • Investors should examine cancellation rights, margins, timing, customer concentration, and execution risk.

How Backlog Works

A company adds to backlog when it receives an order, contract, or commitment that it counts under its backlog policy. The backlog declines as the company delivers products, performs services, ships equipment, completes milestones, or recognizes revenue. New orders can replenish or grow backlog.

For example, an equipment manufacturer may have $1 billion of orders scheduled for production over the next two years. A defense contractor may have multi-year contracts not yet performed. A software company may have contracted subscription revenue that will be recognized over future service periods.

Metric

What it usually captures

What to check

Bookings

New customer commitments signed in a period

Whether they are binding and profitable

Backlog

Unfulfilled contracted or ordered work

Timing, cancellation rights, and margin

Revenue

Amount recognized under accounting rules

Performance obligations and delivery

RPO

Remaining performance obligations under revenue rules

Disclosure scope and expected recognition timing

Backlog and Remaining Performance Obligations

Backlog is a company-defined operating metric, while remaining performance obligations, or RPO, is an accounting disclosure concept under revenue recognition rules. RPO generally relates to transaction price allocated to performance obligations that are unsatisfied or partly unsatisfied.

The two can overlap, but they are not always the same. A company may include items in backlog that are not included in RPO, or exclude items from backlog that accounting rules would treat differently. Investors should read the company's definition and reconciliation rather than assuming the labels match.

Why Investors Track Backlog

Backlog can show demand and future workload. A growing backlog may suggest strong order intake, long-cycle demand, or revenue visibility. A shrinking backlog may signal weak orders, faster delivery than replacement, or a company burning through past demand.

Backlog also matters operationally. If backlog grows too quickly, the company may face capacity constraints, labor shortages, supply-chain pressure, or execution risk. If backlog is old, low-margin, or fixed-price during inflation, it may become less attractive than the headline value suggests.

Quality of Backlog

Investors should ask whether the backlog is firm, funded, cancellable, subject to customer financing, or dependent on regulatory approval. They should also ask when it is expected to convert into revenue and whether the margin profile is healthy.

A backlog filled with profitable, near-term, binding work is very different from a backlog of low-margin, delayed, cancellable projects. Customer concentration matters as well: one large contract can make backlog look strong while increasing dependence on a single buyer.

The Bottom Line

Backlog is contracted or ordered work that has not yet been fulfilled or recognized as revenue. It can be a valuable signal of future activity, but investors should judge its timing, margin, collectability, cancellation risk, and relationship to bookings, billings, revenue, cash flow, and RPO.

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