The short answer
The fixed costs are small and predictable: the Apple Developer Program at 99 USD a year, Apple’s commission on digital sales, and your servers. The real cost of maintenance is engineering time, and most of it is set by Apple’s calendar: a new iOS every autumn, a higher minimum SDK every spring, and new devices. We do not use a percentage-of-build rule of thumb, because the honest number depends on how much your app relies on fast-moving parts.
Apple’s calendar drives most of it
| When | What happens | What it means for you |
|---|---|---|
| June | WWDC: the next iOS is announced and betas begin | Test against the betas, plan what to adopt |
| September | The new iOS and new iPhones ship | Fixes for the new OS, and new screen sizes |
| The following April | The minimum SDK for uploads rises | A rebuild with the current Xcode, deprecated APIs replaced |
| Any time | App Review Guidelines change | Policy updates; see the latest changes |
The current cycle, as an example: since 28 April 2026, uploads need the iOS 26 SDK. iOS 27 arrived in autumn 2026, and iPhone Duo on 23 October 2026. From April 2027, Apple requires the iOS 27 SDK with a deployment target of iOS 15 or later, and iPhone Duo screenshots for apps built with the iOS 27.1 SDK or later.
The fixed costs
- Apple Developer Program: 99 USD per membership year, with local prices in some regions (Apple).
- Commission: 15% of digital sales for Small Business Program members and for subscriptions after their first year, 30% otherwise.
- Servers and databases, if the app has a backend. CloudKit can remove this cost for data that only follows one person across their own devices.
- Third-party services: analytics, crash reporting, sign-in providers and AI APIs, usually billed monthly or per use.
- A support website. The App Store requires a support URL that leads to real contact information.
What tends to need work each year
- Deprecated APIs. Apple deprecated the original StoreKit in-app purchase API in iOS 18, and On-Demand Resources in iOS 27 (details). Deprecated code keeps working for a while, then becomes a forced rewrite.
- Design changes. A new system look, such as Liquid Glass, makes apps that do not adopt it look dated.
- New devices. iPhone Duo is the clearest case in years: apps that size themselves from the screen need fixing. See getting ready for iPhone Duo.
- Third-party SDKs. Each one needs updating, and each update can break something.
- Policy. In 2025 and 2026 alone: disclosure for third-party AI, a social media question in the age rating, and new moderation rules.
Retainer or project by project
Every project we build includes 30 days of support after launch. After that, there are two sensible ways to keep an app current:
- A retainer for updates, new features and new iOS releases. It suits apps that ship regularly, or that depend on subscriptions and cannot afford to fall behind.
- Project by project, for example once a year after WWDC. It suits stable apps with few moving parts.
How to keep maintenance cheap
- Prefer Apple’s frameworks to third-party SDKs. They are updated with the OS, by Apple.
- Update every year, not every three. Small yearly updates cost less than one large catch-up.
- Keep the minimum iOS version reasonable. Supporting very old versions costs testing time with every change.
- Stay on current APIs. For example, use StoreKit 2; Apple’s new subscription features in iOS 27 are built on it.
- Write tests for the parts that earn money: purchase, restore and sign-in.
Related: How much an iOS app costs · App Review Guidelines changes · What’s new in iOS 27