Top 12 C# Development Companies In The UK (2025)

Finding the right C# development company isn’t easy—especially when a quick Google search returns about 41,500,000 of results.

Sorting through them can be time-consuming and overwhelming, and it’s tough to know which company will truly deliver the quality and reliability your project needs.

But don’t worry…

We’ve done the hard work for you and compiled a list of the top 13 C# development companies to help you find the perfect partner for building robust, high-performing software solutions.

What makes a top C# Development Company?

First things first.

Many development firms make big promises but fall short on delivery. That’s why it’s important to know what to look for when choosing a C# development company—and these are the key criteria we used to compile our list.

• Project Portfolio: Evaluate the company’s previous work to understand their technical capabilities and problem-solving approach. Look beyond surface-level design to how they’ve structured applications, implemented features, and met client goals.
• Technical Expertise: A top-tier C# development team should demonstrate deep knowledge of the .NET ecosystem, including frameworks, libraries, and integration best practices. This ensures scalable, maintainable, and secure solutions.
• Industry Experience: Development companies with experience in your industry are more likely to understand your specific challenges and requirements—leading to faster delivery, fewer revisions, and software that fits your business like a glove.

Top C# Development Companies

1. 6B

We’re 6B, a leading C# development company known for building scalable, high-performance software solutions tailored to your business needs.

Whether you’re looking to develop enterprise-grade applications, modernise legacy systems, or build robust back-end infrastructures, our expert C# development team is here to deliver.

At 6B, we handle every aspect of the development process—from technical architecture and coding to deployment and ongoing support—ensuring a seamless experience and top-tier results.

Our team includes senior .NET developers, solution architects, QA engineers, and project managers, all working collaboratively to deliver reliable, maintainable software built to scale.

We’ve earned recognition as one of the top software development firms in the UK, trusted by public sector organisations, fast-growing startups, and enterprise clients alike.

With a growing team, a reputation for technical excellence, and offices in Wakefield and Portugal, 6B is the trusted partner for businesses that demand serious C# expertise.

So, if you’re looking to build powerful, scalable software with a top-tier C# development team, get in touch with us by clicking the button below. Or, if you’d like to learn more about our C# development services, then check out our service page here.

Get in touch with our C# Development team

2. Zudu

Zudu is an award-winning software development agency based in the UK, known for delivering bespoke solutions using C# and the .NET framework. Their team specialises in building scalable, secure web and mobile applications, with strong expertise in cross-platform development and enterprise-grade systems.

3. Empat

Empat is a full-cycle software development agency with offices in London , Kyiv, and San Francisco, delivering mobile and web applications across industries. Their team—many with strong IT and mathematics backgrounds—leverages C# and the .NET ecosystem to build scalable, secure, enterprise-grade systems for startups, scale-ups, and Fortune-level clients. With over 300 successful projects and perfect Clutch scores, Empat offers proven .NET expertise for high-quality, full-stack software solutions. Services include:

• Custom mobile app development (iOS, Android, cross-platform)
• Custom web and SaaS development, including CRM/ERP, dashboards, and marketplaces
• Full-cycle product development from MVP through launch and scaling
• CTO-as-a-Service and technical consulting for startups
• IT outstaffing and team augmentation to support project growth

4. Blott

Blott is a design-led development agency based in London (with teams across New York, Cape Town and Colombo) that delivers custom software, mobile, web and AI solutions. Their development team includes skilled C#/.NET engineers who build secure, high-performance applications—particularly for fintech and enterprise clients—leveraging ASP.NET and the Microsoft ecosystem to create scalable, maintainable systems.

5. InStandart

InStandart is a UK-based bespoke software developer renowned for its expertise in C# and the .NET ecosystem, delivering robust, secure, and scalable applications across web, desktop, and CAD integrations. Their C#/.NET team builds enterprise-grade solutions tailored to fintech, e-commerce, real estate, and automation industries using technologies like WPF, .NET AutoCAD API, and ASP.NET.

6. Matellio

Matellio is a bespoke software development firm headquartered in the UK, highly proficient in C# and the .NET ecosystem. Their .NET team delivers end-to-end solutions—from ASP.NET web apps and cross-platform mobile development with Xamarin to enterprise-grade microservices, cloud integration, machine learning and IoT systems—tailored for scalable, secure, high-performance applications.

7. Lilo

Lilo is a UK-based digital agency with specialised expertise in C# and the .NET ecosystem, offering end-to-end development of bespoke web, mobile, desktop, and cloud applications. Their experienced C#/.NET team delivers secure, high-performance systems—ranging from ASP.NET Core websites and WPF desktop apps to Xamarin mobile solutions—alongside seamless legacy migrations, API integrations, and Microsoft Azure-based deployments.

8. Audacia

Audacia is a Microsoft‑certified .NET development agency based in Leeds and London, specialising in building complex, scalable, secure C# applications across web, mobile, cloud, ML and backend platforms. Their expert team leverages ASP.NET Core, Xamarin, ML.NET and Azure (or AWS) to deliver mission‑critical enterprise systems—ranging from fintech and healthcare to industrial and public sector projects.

9. Timspark

Timspark is a UK. based software development and IT consulting agency with strong expertise in C#, the .NET ecosystem, and .NET MAUI/Xamarin. Their C#/.NET engineers build scalable, secure backend systems, cross-platform mobile apps, and Unity-powered games for industries like manufacturing, gaming, and enterprise, delivering mission-critical solutions with cloud and IoT integrations.

10. Enlab

Enlab is a UK and offshore custom software developer with a strong focus on C# and the .NET ecosystem. Their experienced team excels in building secure, scalable, and maintainable solutions—ranging from desktop and web applications to robust microservices architectures—while following best practices like SOLID principles, domain‑driven design, and multi‑tiered structures.

11. Hidden Brains

Hidden Brains is a Microsoft-certified C# development agency based in London, delivering bespoke, enterprise-grade applications across web, mobile, cloud, and desktop platforms. Their expert team offers end-to-end C# services—including ASP.NET MVC development, Azure cloud solutions, cross-platform mobile apps, API integrations, legacy migrations, and on-demand consultancy—to help businesses build scalable, secure, high-performance systems.

12. Cool Code Company

Cool Code Company, based in Nottingham, offers bespoke C# development services across web, mobile, desktop, and cloud platforms. Their expert team leverages the full .NET ecosystem—including ASP.NET Core, WPF, WinForms, Xamarin, Azure, and Power Platform—to build tailored, high-performance applications, APIs, and integrations for industries such as manufacturing, education, and e-commerce.

Why Hire One of the Best C# Development Companies?

Quite simply—your business deserves the best.

With so many software agencies out there, finding the right C# development partner is crucial for the long-term success and scalability of your digital product or internal systems.

Whether you’re building complex web applications, automating workflows, or integrating cloud solutions, having a highly skilled C# team ensures your technology is robust, secure, and built to grow with your business.

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