IRU (Indefeasible Right of Use)

An IRU (Indefeasible Right of Use) is a long-term, non-cancellable right to use a specific amount of fiber capacity or dark fiber strands on a telecom route, typically for 15-25 years, without transferring ownership of the underlying cable. Data center operators and network carriers use IRUs to secure diverse fiber paths into a facility or between campuses without building their own long-haul infrastructure, paying an upfront or amortized fee instead of a recurring lease. Because an IRU is treated as a capital asset with a fixed usable life rather than an operating lease, it shows up on the buyer's balance sheet differently than dark-fiber or lit-fiber monthly recurring charges, and its terms typically restrict resale or transfer. IRUs are common in subsea cable consortiums and cross-border metro routes feeding carrier hotels, where hyperscalers and colocation providers lock in capacity years before a route is needed.