Kotlin Developer Salary UK 2025

💷 2025 GBP🇬🇧 UK⚖️ IR35🏙️ City📊 Seniority

Last updated: August 20257 min read • Written by: ClickMasters HR Team • Reviewed by: Reviewed annually

Direct Answer

Kotlin Developer salaries range from £32,000 to £780–£1,080/day. Kotlin Multiplatform (KMP) experience commands growing premium — KMP allows sharing business logic between Android and iOS (competitive with React Native). Kotlin Coroutines expertise commands premium for high-performance Android apps. Kotlin + Spring Boot backend commands premium for Java-shop migrations. Android Jetpack Compose experience commands 15–20% premium over XML-layout-only Android developers.

Market Outlook

Kotlin Developers primarily build Android applications and JVM backend services. Kotlin is Google's preferred language for Android development (replacing Java) and is increasingly used for backend (Ktor, Spring Boot on Kotlin). The UK Kotlin market is primarily Android-focused but growing in backend contexts.

Salary benchmarks by Seniority

Seniority
Permanent Salary
Day Rate (Outside IR35)
Annual Equivalent
Junior (0–2 yrs)
£32,000–£52,000
£250–£415/day
£46,650–£77,439
Mid-Level (3–5 yrs)
£52,000–£88,000
£415–£630/day
£77,439–£117,558
Senior (6–10 yrs)
£88,000–£130,000
£590–£840/day
£110,094–£156,744
Principal / Staff Kotlin (10+ yrs)
£122,000–£175,000
£780–£1,080/day
£145,548–£201,528

IR35 Tax Position

Day rates assume outside IR35. Inside IR35 contractor day rates in the UK are typically 15–25% higher to compensate for the lack of tax efficiency and additional payroll costs. ClickMasters engineers are directly employed by us, representing **zero IR35 risk** for clients.

Frequently Asked Questions

Everything you need to know about kotlin developer salary standards.

Approximately £88,000–£130,000 mid-level. London +20–30%.

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