IFRS 15 can pose unique challenges to various industries, as its principles-based approach may require significant judgment in certain areas.

Here are some potential challenges in specific industries:

1. Real Estate: Determining whether control of a property is transferred over time or at a point in time can be complex. It may not always be clear when a customer obtains control of a work in progress in long-term property development contracts. Also, the treatment of variable consideration (such as sales incentives, rebates, or refunds) can be challenging.
2. Construction: The construction industry typically involves long-term contracts that may contain multiple performance obligations, changes in contract terms, and variable considerations. Identifying performance obligations, determining whether they are distinct, and allocating the transaction price to these obligations may be complex. The timing of revenue recognition (over time vs. point in time) can also be a significant issue in construction contracts.
3. Telecommunications: Telecommunication companies often bundle goods and services (like a phone and a service plan). Determining standalone selling prices for goods or services that are not sold separately and allocating the transaction price can be challenging. The treatment of contract modifications, such as upgrades, and the associated timing of revenue recognition can also be complex.

In each of these industries, the disclosure requirements under IFRS 15 may also require entities to gather and present data in ways they have not previously done. Transitioning to the standard can thus require significant efforts in terms of process changes, staff training, and systems upgrades.

Moreover, because IFRS 15 affects revenue, one of the most critical financial metrics, its implementation can have far-reaching effects on entities' financial results, key performance indicators, contractual arrangements, budgeting, and more.