Kotlin Developer Salary UK 2026

💷 2026 GBP🇬🇧 UK⚖️ IR35🏙️ City📊 Seniority

Last updated: March 20267 min read • Written by: ClickMasters HR Team • Reviewed by: Reviewed annually

Direct Answer

Kotlin Developer salaries range from £30,000 to £780–£1,120/day. Kotlin with Jetpack Compose (Android UI toolkit — declarative UI replacing XML layouts) commands premium. Kotlin with Kotlin Multiplatform (KMP — shared Kotlin business logic with iOS Swift UI) commands growing premium as KMP adoption increases in UK enterprise. Kotlin with NHS Android App integration (NHS Login on Android, DTAC Android compliance) commands NHS premium. Kotlin backend (Spring Boot Kotlin — replacing Java Spring Boot in UK enterprise) commands premium for senior engineers comfortable in JVM server-side context.

Market Outlook

Kotlin Developers write Android mobile applications and JVM backend services. Kotlin is the official Android development language (replacing Java) — all new Android development in UK should be Kotlin not Java. Kotlin Multiplatform (KMP) — sharing business logic between Android and iOS — is growing in 2026 but not yet mainstream.

Salary benchmarks by Seniority

Seniority
Permanent Salary
Day Rate (Outside IR35)
Annual Equivalent
Junior Kotlin (0–2 yrs)
£30,000–£50,000
£235–£400/day
£43,851–£74,640
Mid Kotlin (3–5 yrs)
£50,000–£85,000
£400–£605/day
£74,640–£112,893
Senior Kotlin (6–10 yrs)
£85,000–£128,000
£570–£820/day
£106,362–£153,012
Principal / Lead Kotlin (10+)
£122,000–£180,000
£780–£1,120/day
£145,578–£209,040

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 £85,000–£128,000 mid-level. London +20–30%.

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