Choosing the right .NET development partner can have a long-term impact on how successfully a digital product evolves. The UK market offers a broad range of software companies, from specialized .NET consultancies to full-service technology partners with extensive enterprise experience. This guide highlights companies recognized for their technical expertise, delivery capabilities, and ability to build scalable solutions tailored to different business needs. Whether you're planning a new platform, modernizing existing software, or expanding your development capacity, these providers represent some of the strongest options available in the UK market.

1. Oski Solutions

At Oski Solutions, we develop software products and digital platforms with a strong focus on practical engineering, maintainability, and long-term business needs. Our work with .NET technologies is part of a broader approach that combines cloud infrastructure, frontend development, AI integration, and modern software delivery practices. We build web, mobile, and desktop applications, paying close attention to architecture, performance, security, and the day-to-day realities of operating software in production environments.

We work with companies across different markets and industries, including organizations operating in the UK, where scalable and reliable .NET solutions continue to play an important role in enterprise software development. Our teams support projects at different stages, from early product development to modernization and ongoing platform evolution. Alongside software engineering, we focus on development processes, automation, testing, and operational stability to help teams maintain consistent delivery over time.

Key Highlights:

• Experience in .NET software development and cloud-based architectures

• Development of web, mobile, and desktop applications

• Expertise in Azure, AWS, serverless, and hybrid cloud environments

• Integration of AI, machine learning, and data-driven functionality

• Experience with CI/CD pipelines and DevOps practices

• Work across industries including fintech, logistics, e-commerce, education, and insurance

• Focus on software maintainability, observability, and operational reliability

Services:

• .NET development

• ASP.NET web application development

• Cloud-native and serverless application development

• API development and backend engineering

• Enterprise software modernization

• DevOps implementation and CI/CD automation

• AI and data integration services

• Software maintenance and platform support

Contact Information:

• Website: oski.site

• E-mail: [email protected]

• LinkedIn: www.linkedin.com/company/oski-solutions

• Address: Kaupmehe tn 7, 10114 Tallinn, Estonia

• Phone: +48571282759

2. i-finity

i-finity develops custom .NET applications with a focus on cloud technologies, business software, and long-term application support. Their work is closely connected with the Microsoft ecosystem, including Azure services, .NET development, and Umbraco-based platforms. The company works on projects ranging from SaaS products and enterprise applications to custom business systems and software modernization initiatives.

Alongside application development, they support cloud migration, infrastructure improvements, and ongoing maintenance activities. Their experience with Microsoft technologies extends across sectors such as financial services, industrial software, smart devices, and business operations platforms, where security, scalability, and system reliability are important considerations.

Key Highlights:

• Microsoft-focused software development expertise

• Experience with .NET and Azure ecosystems

• Development of SaaS and enterprise applications

• Umbraco CMS implementation capabilities

• Legacy application modernization experience

• Cloud migration and infrastructure services

• Long-term software support and maintenance

Services:

• Custom .NET application development

• ASP.NET web development

• SaaS application development

• Azure cloud migration

• Umbraco CMS development

• Legacy software modernization

• Application maintenance and support

Contact Information:

• Website: www.i-finity.co.uk

• Email: [email protected]

• Facebook: www.facebook.com/IFinityHQ

• Twitter: x.com/ifinityhq

• LinkedIn: www.linkedin.com/company/i-finity

• Instagram: www.instagram.com/ifinityhq

• Address: Blake House, 66 Bootham, York, YO30 7BZ

• Phone: 01904652100

3. chilliapple

chilliapple develops .NET applications for businesses looking to build new digital products or extend existing software systems. Their work covers web applications, enterprise platforms, SaaS products, and business process software built with Microsoft technologies and related frameworks. They also work with cloud platforms, integrations, and cross-platform application development.

Their projects often combine backend engineering, frontend development, and business system integrations to support different operational requirements. Alongside custom development, they provide modernization services, application maintenance, and support for organizations looking to improve the performance and maintainability of existing .NET environments.

Key Highlights:

• Experience with ASP.NET and .NET Core development

• Development of SaaS and enterprise applications

• Cross-platform software engineering capabilities

• Application modernization services

• Integration with cloud platforms and third-party systems

• Experience with AI, IoT, and data-driven applications

• Ongoing support and maintenance services

Services:

• Custom .NET application development

• Enterprise software development

• SaaS platform development

• Web and mobile application development

• Application modernization

• API and third-party integrations

• Software maintenance and support

• Cloud application development

Contact Information:

• Website: www.chilliapple.co.uk

• Email: [email protected]

• Facebook: www.facebook.com/ChilliappleLimited

• Twitter: x.com/chilliapple

• LinkedIn: www.linkedin.com/company/chilliapple-ltd

• Instagram: www.instagram.com/chilliappleltd

• Address: 16 Upper Woburn Place, London, WC1H 0AF, United Kingdom

• Phone: 01732 753 101

4. Dune Technology

Dune Technology develops .NET applications as part of its broader software product and team augmentation services. Their delivery model combines local project management with distributed engineering teams, supporting companies that need additional development capacity or end-to-end product delivery. .NET development is used across business applications, custom platforms, and digital products.

The company works closely with client teams throughout the development process, from early planning and implementation to ongoing maintenance and improvements. Their approach places emphasis on collaboration, iterative delivery, and maintaining software quality while supporting projects across different industries and business domains.

Key Highlights:

• Custom .NET software development

• Team augmentation and product delivery services

• Experience with web and business applications

• Agile software development practices

• Distributed engineering team model

• Ongoing support and maintenance capabilities

Services:

• Custom .NET development

• Enterprise application development

• Team augmentation

• Product development services

• Application modernization

• DevOps and cloud services

Contact Information:

• Website: www.dunetech.co.uk

• Email: [email protected]

• LinkedIn: www.linkedin.com/company/dunetechnology

• Address: 71–75 Shelton Street, Covent Garden, London, WC2H 9JQ

5. net-devs

net-devs develops enterprise software using a model where experienced engineers oversee architecture, delivery, and quality control, while AI tools are used to accelerate implementation tasks. Their engineering teams work across multiple technology stacks, with .NET representing one of the core platforms used for enterprise applications, cloud systems, and business platforms.

A significant part of their work involves cloud-native development, platform engineering, and modernization projects. They also collaborate with companies operating in the UK market, where enterprise organizations continue to invest in scalable .NET ecosystems and cloud-based business applications. Their delivery process combines automated workflows with direct engineering ownership throughout the project lifecycle.

Key Highlights:

• Senior-led software engineering teams

• Experience with enterprise .NET development

• AI-assisted software delivery processes

• Cloud-native architecture expertise

• Multi-cloud platform engineering capabilities

• Focus on software quality and maintainability

• Support for enterprise modernization projects

Services:

• Enterprise .NET development

• Cloud application development

• Platform engineering

• Software modernization

• AI engineering services

• Frontend application development

• Testing and quality assurance

• Ongoing software support

Contact Information:

• Website: net-devs.com

• Email: [email protected]

• LinkedIn: www.linkedin.com/company/net-devs

• Address: Obrzeżna 1D, 02-691 Warszawa, Poland

• Phone: +48 571 282 759

6. TatvaSoft

TatvaSoft provides .NET software development services across a wide range of business environments, from internal enterprise systems to cloud-based applications and SaaS platforms. Their work with Microsoft technologies spans different frameworks and architectures, including ASP.NET, .NET Core, C#, MVC, and Xamarin. Alongside application development, they also work with cloud platforms, system integrations, and software modernization projects.

The company approaches .NET development as part of a broader software ecosystem that includes infrastructure, testing, deployment, and ongoing application management. Their experience covers projects in sectors such as finance, healthcare, retail, logistics, and education, where scalable and maintainable software systems remain a core requirement for business operations.

Key Highlights:

• Experience with Microsoft .NET technologies and enterprise software

• Development of web, desktop, mobile, and SaaS applications

• Expertise in ASP.NET, .NET Core, C#, MVC, and Xamarin

• Cloud application development using Microsoft Azure

• Enterprise application integration and modernization

• Support for dedicated development team models

• Experience across multiple business sectors

Services:

• Custom .NET application development

• ASP.NET web application development

• .NET Core development

• Enterprise software integration

• Azure cloud application development

• Legacy application modernization

• Cross-platform mobile development

• Application support and maintenance

Contact Information:

• Website: www.tatvasoft.co.uk

• Email: [email protected]

• Facebook: www.facebook.com/TatvaSoft

• Twitter: x.com/tatvasoft

• LinkedIn: www.linkedin.com/company/tatvasoft

• Address: 307, Euston Road, London NW1 3AD, United Kingdom

• Phone: +44 742 409 8452

7. Fast Fwd

Fast Fwd develops .NET web applications for businesses that require scalable and maintainable digital platforms. Their work with ASP.NET and related Microsoft technologies covers custom web applications, enterprise systems, application integrations, and modernization projects. The company combines backend development with design, digital strategy, and DevOps capabilities as part of its software delivery process.

Their approach to .NET development places a strong emphasis on collaboration between developers, designers, project managers, and other specialists involved in the product lifecycle. Beyond initial implementation, they also provide ongoing maintenance and support for applications that continue to evolve alongside business requirements.

Key Highlights:

• Focus on ASP.NET web application development

• Experience with enterprise-grade software projects

• Full-cycle software development capabilities

• Cross-functional delivery teams

• Legacy application migration and modernization

• Integration with third-party systems and platforms

Services:

• Custom .NET web development

• ASP.NET application development

• Application integration services

• Legacy system migration

• Enterprise web application development

• Software maintenance and support

Contact Information:

• Website: www.fastfwd.com

• Email: [email protected]

• Address: Suite 3, Falcon Works House, 40 Regent Pl, Birmingham B1 3NN, UK

• Phone: +44 121 236 8007

8. A-listware

A-listware works with organizations that need additional software engineering capacity, dedicated development teams, or support for complex digital products. Microsoft .NET is one of the core backend technologies within their engineering practice, alongside a broader set of cloud, data, infrastructure, and enterprise software capabilities. Their delivery model combines software development with team management, consulting, and operational support.

The company participates in projects across industries such as finance, healthcare, manufacturing, logistics, and professional services. In addition to application development, they support modernization initiatives, cloud migration, analytics platforms, and long-term software maintenance, depending on the requirements of each project.

Key Highlights:

• Experience with .NET and enterprise software development

• Dedicated development teams and staff augmentation services

• Cloud, infrastructure, and data engineering capabilities

• Support for software modernization projects

• Experience across multiple industries

• End-to-end software delivery and operational support

• Integration of development and managed services

Services:

• Custom software development

• .NET application development

• Team augmentation

• Enterprise software development

• Legacy system modernization

• Cloud application development

• IT consulting

• Application support and maintenance

Contact Information:

• Website: a-listware.com

• Email: [email protected]

• Facebook: www.facebook.com/alistware

• LinkedIn: www.linkedin.com/company/a-listware

• Address: St. Leonards-On-Sea, TN37 7TA, UK

• Phone: +44 (0)142 439 01 40

9. 21Century.tech

21Century.tech builds software products using a delivery model that combines senior engineering oversight with AI-assisted development workflows. Their approach focuses on accelerating implementation tasks while keeping architectural decisions, quality assurance, and final delivery under the responsibility of experienced engineers. This model is applied across product development, system integrations, and software modernization projects.

The company works with modern software stacks and development practices, including cloud-native architectures, automated testing, and continuous delivery processes. Teams operate remotely and collaborate with companies in different markets, including businesses in the UK that are looking to shorten delivery cycles without removing engineering ownership from the development process.

Key Highlights:

• AI-assisted software development workflows

• Senior-led engineering teams

• Focus on rapid product delivery cycles

• Human-reviewed development processes

• Experience with software modernization

• Cloud-native and CI/CD practices

• Remote-first delivery model

Services:

• Custom software development

• AI-augmented product development

• Full-stack application development

• Software modernization

• API and third-party integrations

• Cloud infrastructure implementation

• CI/CD setup and automation

Contact Information:

• Website: 21century.tech

• Email: [email protected]

10. Hidden Brains

Hidden Brains provides .NET and ASP.NET Core development services for businesses that require web applications, enterprise systems, APIs, and cross-platform solutions. Their work covers projects for startups, small businesses, and larger organizations across sectors such as healthcare, logistics, finance, retail, and education. The company develops applications using modern .NET technologies, including cloud-based and microservices architectures.

Beyond custom development, Hidden Brains supports migration projects, system integration, and application maintenance. Their approach to .NET development includes building scalable backend systems, implementing third-party integrations, and maintaining existing enterprise applications over the long term.

Key Highlights:

• ASP.NET and ASP.NET Core expertise

• Cross-platform application development

• Enterprise software development

• API development and integration

• Cloud and microservices architecture

• Legacy system migration

• Application maintenance and support

• Experience across multiple industries

Services:

• ASP.NET development

• ASP.NET Core development

• Enterprise application development

• Custom web development

• API development and integration

• Application migration

• Cross-platform development

• Application support and maintenance

Contact Information:

• Website: www.hiddenbrains.co.uk

• Email: [email protected]

• Facebook: www.facebook.com/HiddenBrains

• Twitter: x.com/HiddenBrains

• LinkedIn: www.linkedin.com/company/hiddenbrains-infotech

• Address: Unit P Hunting Gate, East Portway, Andover, Hampshire, SP10 3ER, United Kingdom

• Phone: +44 207 993 2188

11. SoftPro

SoftPro focuses on custom software development using Microsoft technologies, including ASP.NET, .NET Core, Azure, and related enterprise tools. Their projects include business portals, CRM and HRM systems, SaaS platforms, and web applications designed to support operational processes and digital transformation initiatives.

The company combines backend development, cloud technologies, and system architecture design to create solutions adapted to specific business requirements. Their technical expertise also extends to cloud development, artificial intelligence applications, and enterprise software modernization.

Key Highlights:

• Microsoft technology stack expertise

• ASP.NET and .NET Core development

• Azure cloud solutions

• CRM and HRM system development

• SaaS platform development

• Enterprise software architecture

• AI integration capabilities

• Custom software engineering

Services:

• Custom software development

• ASP.NET development

• .NET Core development

• Cloud development

• Web application development

• CRM and HRM systems

• SaaS platform development

• AI solutions

Contact Information:

• Website: soft-pro.pl

• Address: Erazma Ciołka 13, 01-445 Warszawa, Poland

12. Takeoff Digital

Takeoff Digital develops .NET-based applications for organizations that require custom software, web platforms, APIs, and enterprise systems. Their work with the Microsoft ecosystem includes ASP.NET, ASP.NET MVC, Web API services, Entity Framework, and Office integrations.

Their development process emphasizes software architecture, maintainability, and integration with existing business systems. Alongside custom software creation, they support ongoing maintenance, application scaling, and modernization of existing platforms.

Key Highlights:

• Microsoft .NET ecosystem expertise

• ASP.NET MVC development

• Web API and REST services

• Entity Framework implementation

• Office application integration

• Enterprise software architecture

• Software maintenance services

• Custom business applications

Services:

• Custom software development

• ASP.NET development

• ASP.NET MVC development

• API development

• Enterprise application development

• Software maintenance

• System integration

• Database solutions

Contact Information:

• Website: takeoffdigital.co.uk

• Email: [email protected]

• LinkedIn: www.linkedin.com/company/takeoff-digital-uk

• Address: 9 Crown St W, DT1 3FQ, Poundbury, Dorchester, Dorset, United Kingdom

• Phone: 0330 043 2162

13. Virva Infotech

Virva Infotech develops .NET applications for businesses that require secure web platforms, enterprise software, cloud-native systems, and custom business applications. Their technology stack includes .NET, ASP.NET, cloud services, API integrations, microservices, and modern DevOps practices. The company works with organizations at different stages of growth, supporting both new software development and modernization projects.

Their approach to .NET development covers the full application lifecycle, from architecture planning and implementation to deployment and long-term support. The solutions they build often include real-time functionality, cloud infrastructure, business dashboards, and integrations with existing enterprise systems. Particular attention is given to scalability, security, and operational reliability.

Key Highlights:

• Experience with .NET and ASP.NET development

• Enterprise application development capabilities

• Microservices architecture implementation

• Cloud-native application development

• API and third-party system integration

• DevOps and CI/CD practices

• Legacy system modernization

• Multi-tenant SaaS architecture experience

Services:

• Custom .NET application development

• ASP.NET web development

• Enterprise software development

• API development and integration

• Cloud application development

• Legacy application modernization

• DevOps implementation

• Application maintenance and support

Contact Information:

• Website: www.virvainfotech.co.uk

• Email: [email protected]

• Facebook: www.facebook.com/61558434935001

• Twitter: x.com/Virva_Infotech

• LinkedIn: www.linkedin.com/company/virva-infotech

• Instagram: www.instagram.com/virvainfotech

• Address: 60 Tottenham Court Road, Suite 7187a, Fitzrovia, London, W1T 2EW, United Kingdom

• Phone: +44 203 432 3984

14. Whiz Solutions

Whiz Solutions provides ASP.NET development services for businesses that require scalable web applications, enterprise platforms, and system integration projects. Their experience includes developing high-traffic applications, large e-commerce systems, and custom business software built on Microsoft technologies. The company also supports migration projects and long-term development engagements.

In addition to software implementation, they focus on project management, quality assurance, and maintaining existing applications as business requirements evolve. Their portfolio includes projects involving complex databases, external integrations, and applications designed to support large user bases and business-critical operations.

Key Highlights:

• ASP.NET development expertise

• Enterprise web application development

• Large-scale database implementation

• Third-party system integration

• Legacy system migration

• Dedicated development team support

• Experience across multiple industries

Services:

• ASP.NET application development

• Enterprise software development

• System integration

• Application migration

• E-commerce platform development

• Dedicated development teams

• Quality assurance and testing

Contact Information:

• Website: www.whizsolutions.co.uk

• Email: [email protected]

• Facebook: www.facebook.com/whizsolutionsltd

• Twitter: x.com/whizsolutionsUK

• LinkedIn: www.linkedin.com/company/whiz-solutions-ltd

• Address: Suite 32, Winsor & Newton Building, Whitefriars Avenue, Harrow, England, HA3 5RN, United Kingdom

• Phone: +44 (0) 742 715 4931

15. Hyperlink InfoSystem

Hyperlink InfoSystem develops .NET solutions for organizations operating in regulated and operationally complex industries, including finance, healthcare, manufacturing, logistics, and the public sector. Their .NET services cover custom application development, enterprise software, system integration, cloud platforms, and modernization of legacy systems. A significant part of their work involves projects where compliance, data governance, and interoperability requirements influence technical decisions.

Their approach to software engineering combines architecture planning, continuous testing, cloud deployment, and long-term operational support. The company also works with organizations in the UK market that require applications aligned with local regulatory frameworks, enterprise infrastructure, and industry-specific operational processes.

Key Highlights:

• Enterprise .NET development experience

• ASP.NET application development

• Legacy system modernization

• Azure cloud implementation

• Enterprise system integration

• Experience with regulated industries

• Long-term application support

• Dedicated development team services

Services:

• Custom .NET application development

• ASP.NET web development

• API and system integration

• Azure cloud development

• Legacy software modernization

• Enterprise software development

• Dedicated .NET teams

• Application maintenance and support

Contact Information:

• Website: www.hyperlinkinfosystem.com

• Email: [email protected]

• Facebook: www.facebook.com/Hyperlink-infosystem-140449209446270

• Twitter: x.com/hyperlinkinfo

• LinkedIn: www.linkedin.com/company/hyperlinkinfosystem

• Instagram: www.instagram.com/hyperlinkinfosystem_

• Address: Level 30, The Leadenhall Building, 122 Leadenhall Street, London EC3V 4AB

• Phone: +44 20 3287 9060

16. Blue Frontier

Blue Frontier develops .NET applications for organizations that require custom software, cloud platforms, desktop applications, and cross-platform mobile solutions. Their engineering teams work with modern Microsoft technologies, including .NET, .NET MAUI, cloud services, and enterprise application frameworks. The company supports projects across industries such as healthcare, finance, public services, and technology.

Software development is combined with design, consulting, infrastructure, and long-term support services, allowing projects to evolve beyond the initial release phase. Their experience includes maintaining existing .NET systems, developing new business applications, and implementing cross-platform solutions using a shared codebase approach.

Key Highlights:

• .NET and .NET MAUI expertise

• Cross-platform application development

• Enterprise software development

• Cloud and web application capabilities

• Experience with healthcare and public sector projects

• Software modernization and maintenance

• Agile software delivery processes

• Dedicated in-house engineering teams

Services:

• Custom .NET development

• Cross-platform mobile development

• Enterprise application development

• Cloud application development

• Desktop software development

• Software modernization

• Application support and maintenance

• Technical consulting

Contact Information:

• Website: www.bluefrontier.co.uk

• Email: [email protected]

• Facebook: www.facebook.com/bluefrontiercouk

• LinkedIn: www.linkedin.com/company/bluefrontier

• Instagram: www.instagram.com/blue_frontier

• Address: Desklodge House, 2 Redcliffe Way, Bristol, BS1 6NL, UK

• Phone: +44 (0)1173 741 774

17. Sapphire Software Solutions

Sapphire Software Solutions develops .NET and .NET Core applications for businesses that require scalable web platforms, enterprise software, APIs, and cloud-based systems. Their experience with the Microsoft ecosystem includes work with .NET Core, Azure services, microservices architecture, and enterprise application development. They support both new product development and modernization projects involving existing software platforms.

The company also works on integrations, cloud migration, and long-term application support. Their .NET development activities extend across industries such as healthcare, finance, logistics, retail, education, and automotive services. In addition to traditional enterprise applications, they incorporate technologies such as AI, IoT, data analytics, and cloud infrastructure into selected software projects where these capabilities are required.

Key Highlights:

• Experience with .NET and .NET Core development

• Enterprise application development capabilities

• API development and third-party integrations

• Cloud-native application development

• Microservices architecture implementation

• Legacy system migration and modernization

• Experience with Azure and DevOps practices

• Cross-industry software development expertise

• Application maintenance and long-term support

Services:

• Custom .NET application development

• ASP.NET web development

• Enterprise software development

• .NET migration and modernization

• Web API development

• Third-party system integration

• Cloud application development

• AI-powered software solutions

• Application maintenance and support

Contact Information:

• Website: www.sapphiresolutions.net

• Email: [email protected]

• Facebook: www.facebook.com/SapphireSoftwareSolution

• Twitter: x.com/SapphireSoftwa

• LinkedIn: www.linkedin.com/company/sapphire-software-solutions

• Instagram: www.instagram.com/sapphiresoftwaresolutions

• Address: 42 Audley Avenue, Gillingham,ME73AY United Kingdom

• Phone: +91-942-970-9662

Conclusion

When evaluating .NET development companies in the UK, there is no single approach that fits every business. Some organizations focus on enterprise platforms and long-term software maintenance, while others specialize in cloud-native applications, product development, or dedicated engineering teams. The right choice often depends less on company size or market presence and more on technical alignment, industry experience, and the ability to support a project's goals over time.

The companies featured in this list represent different approaches to .NET development, from traditional enterprise software engineering to modern cloud, AI, and cross-platform solutions. Whether the priority is building a new product, modernizing existing systems, or extending internal development capabilities, the UK market continues to offer a broad range of experienced .NET partners capable of supporting complex business and technology requirements.