London is home to companies building software for banks, fintech businesses, and financial organisations that need secure platforms, integrations, and customer-facing products. This list covers providers working with banking applications, payment infrastructure, core system modernisation, and related financial technology projects.
1. Itexus
Itexus builds custom banking and fintech software for banks, fintech companies, investment businesses, and other regulated service providers. Its banking projects include digital banking platforms, payment solutions, lending systems, and digital wallets. Itexus also builds customer onboarding, KYC workflows, card management, and integrations with existing financial infrastructure.
Itexus works on new financial products and also modernizes existing systems. Its teams build web and mobile apps, backend platforms, and cloud solutions. They also handle data engineering, quality assurance, and connections to banking APIs and third-party services.
Key Facts
- Best for: Banks and fintech companies building custom financial platforms
- Core services: Banking software development, fintech applications, payment systems, lending platforms
- Specialization: Digital banking, financial integrations, regulated software products
- Location: Global delivery with European development offices
- Notable strength: Experience with complex fintech systems and banking workflows
Contact Information
- Website: itexus.com
- Email: moc.suxeti@ofni
- Address: Twarda 14, 00-824 Warszawa, Poland
- LinkedIn: www.linkedin.com/company/itexus
- Facebook: www.facebook.com/itexus
- Twitter: x.com/ItexusSoft
- Instagram: www.instagram.com/itexus.soft
2. ELEKS
ELEKS builds software for financial institutions: banking apps, payment solutions, data platforms, and enterprise software. Typical projects involve digital banking, customer portals, transaction processing, and links to existing banking systems.
Its fintech services cover software architecture, app development, QA, cybersecurity, cloud engineering, and data work. ELEKS also helps banks replace older systems without disrupting daily operations.
Key Facts
- Best for: Financial organisations requiring custom engineering services
- Core services: Banking software, cloud solutions, data engineering, QA
- Specialization: Enterprise software and financial technology
- Industries: Banking, finance, insurance
- Location: London, UK
Contact Information
- Website: www.eleks.com
- Phone: +44-20-4583-0843
- Email: moc.skele@ofniskele
- Address: Moor Place, 1 Fore Street Avenue, London, United Kingdom, EC2Y 9DT
- LinkedIn: www.linkedin.com/company/eleks
- Facebook: www.facebook.com/ELEKS.Software
- Twitter: x.com/ELEKSSoftware
3. Andersen
Andersen builds banking software for financial companies from its London office. It works on digital banking apps, payment systems, lending platforms, customer management tools, and links between banking services.
Its teams cover the full cycle, from design and architecture to build and maintenance. Andersen also has experience with AML, KYC, PSD2, and GDPR requirements, cloud platforms, and banking system integrations.
Key Facts
- Best for: Banks needing custom software development and dedicated teams
- Core services: Digital banking, payment software, lending platforms, integrations
- Specialization: Financial software development and enterprise applications
- Location: London, UK
- Notable strength: Experience with regulated software environments
Contact Information
- Website: andersenlab.com
- Phone: +44 207 048 6755
- Email: moc.balnesredna@nv
- Address: 1 St Katharine's Way, 6th floor, London E1W 1YL, UK
- LinkedIn: www.linkedin.com/company/andersen-lab
- Facebook: www.facebook.com/AndersenSoftwareDev
- Twitter: x.com/AndersenLabs
- Instagram: www.instagram.com/andersen.global
4. Vention
Vention builds software for fintech and banking companies, including payments, digital banking, investment platforms, and financial apps. Its London team can add engineers to an existing team or build a whole product.
Vention develops APIs, backend systems, mobile apps, and financial services platforms. It also handles open banking integrations, modernizes older systems, and supports companies building regulated financial products.
Key Facts
- Best for: Fintech companies requiring flexible engineering support
- Core services: Banking applications, APIs, software development, modernisation
- Specialization: Fintech, payments, investment software
- Location: London, UK
- Notable strength: Supports different engagement models
Contact Information
- Website: ventionteams.com
- Phone: +442071172842
- Email: moc.smaetnoitnev@olleh
- Address: London, 30 Churchill Place, E14 5RE
- LinkedIn: www.linkedin.com/company/ventionteams
- Twitter: x.com/ventionteams
- Instagram: www.instagram.com/ventionteams
5. Scott Logic
Scott Logic helps financial organizations with software engineering, technology consulting, cloud, and digital product development. It knows banking environments, where reliability, security, and links to existing systems matter.
Its services include app development, platform modernization, data work, architecture consulting, and customer experience design. Scott Logic fits banks that need a planned technology change, not a one-off software project.
Key Facts
- Best for: Banks modernising complex technology environments
- Core services: Software engineering, cloud, data, application modernisation
- Specialization: Enterprise financial systems
- Industries: Banking, finance, government
- Location: London, UK
Contact Information
- Website: www.scottlogic.com
- Phone: +44 20 3787 4085
- Email: moc.cigolttocs@yrag
- Address: Office 0109, Cannon Green, 27 Bush Lane, London, EC4R 0AN
- LinkedIn: www.linkedin.com/company/scott-logic-limited
6. Appinventiv
Appinventiv builds fintech and banking software: mobile apps, web platforms, backend systems, and digital financial products. Its London team works with financial companies on customer apps and internal banking tools.
Alongside engineering, Appinventiv offers cloud, AI, data analytics, and cybersecurity work. Its banking projects can include automation, reporting systems, payment features, and apps built around a specific financial workflow.
Key Facts
- Best for: Financial businesses developing digital products
- Core services: Banking software, mobile apps, backend development
- Specialization: Fintech applications and digital platforms
- Location: London, UK
- Notable strength: Combination of product development and emerging technologies
Contact Information
- Website: appinventiv.com
- Phone: + 44 - 753 - 900 - 0641
- Address: 3rd Floor, 86-90 Paul Street, EC2A 4NE London, UK
- LinkedIn: www.linkedin.com/company/appinventiv
- Twitter: x.com/appinventiv
- Instagram: www.instagram.com/appinventiv
7. Limeup
Limeup builds banking apps and financial software from its London office. It works on digital banking platforms, eWallets, payment solutions, account management systems, and customer-facing financial apps.
Its projects cover UX design, frontend and backend development, API integrations, security testing, and ongoing support. Limeup builds custom products that connect to a client's existing financial systems.
Key Facts
- Best for: Companies creating customer-facing banking products
- Core services: Banking apps, payment solutions, UX/UI design, integrations
- Specialization: Digital financial products
- Location: London, UK
- Notable strength: Focus on custom banking applications
Contact Information
- Website: limeup.io
- Phone: +44 20 8135 6600
- Email: oi.puemil@olleh
- Address: Queens House, 180 Tottenham Ct Rd, London W1T 7PD
- LinkedIn: www.linkedin.com/company/limeup
- Facebook: www.facebook.com/limeup.io
- Twitter: x.com/limeup_io
- Instagram: www.instagram.com/limeup.io
8. TatvaSoft
TatvaSoft builds custom software for financial organizations through its UK operations. Its banking work includes lending platforms, financial workflows, reporting systems, and apps for business processes.
The company develops web and mobile apps, cloud solutions, and enterprise platforms. It also maintains software, modernizes older apps, and provides development teams.
Key Facts
- Best for: Financial organisations needing custom enterprise software
- Core services: Financial software, web applications, cloud development
- Specialization: Business process automation and enterprise systems
- Location: London, UK
- Notable strength: Long-term software development support
Contact Information
- Website: www.tatvasoft.com
- Phone: +44 742 409 8452
- Email: moc.tfosavtat@ofni
- Address: 307, Euston Road, London NW1 3AD, United Kingdom
- LinkedIn: www.linkedin.com/company/tatvasoft
- Facebook: www.facebook.com/TatvaSoft
- Twitter: x.com/tatvasoft
9. N-iX
N-iX provides engineering for financial organizations: it modernizes banking systems and builds payment integrations, data platforms, and automation. It fits businesses with complex technology setups.
For banks, N-iX handles API connectivity, compliance automation, customer lifecycle management, risk solutions, and moves to the cloud.
Key Facts
- Best for: Banks modernising technology infrastructure
- Core services: Banking software, cloud, integrations, data solutions
- Specialization: Enterprise financial technology
- Location: London, UK
- Notable strength: Experience with large-scale software projects
Contact Information
- Website: www.n-ix.com
- Phone: +442037407669
- Email: moc.xi-n@tcatnoc
- Address: London, EC3A 7BA, 6 Bevis Marks
- LinkedIn: www.linkedin.com/company/n-ix
- Facebook: www.facebook.com/N.iX.Company
- Twitter: x.com/N_iX_Global
10. Itransition
Itransition builds software for financial organizations, including banking platforms, payment systems, analytics, and enterprise apps. Its teams take on custom development, integration, and modernization projects.
Itransition works on both customer-facing banking products and internal financial systems. Its skills include app development, cloud, data analytics, and automation.
Key Facts
- Best for: Organisations improving existing banking software
- Core services: Banking systems, integrations, cloud development
- Specialization: Enterprise application development
- Location: London, UK
- Notable strength: Experience with complex software environments
Contact Information
- Website: www.itransition.com
- Phone: +447464999606
- Email: moc.noitisnarti@ofni
- Address: Office 3-01, 3rd Floor, 3 Shortlands, W6 8DA
- LinkedIn: www.linkedin.com/company/itransition
- Facebook: www.facebook.com/Itransition
- Twitter: x.com/itransition
11. Zudu
Zudu builds custom software products for businesses, including financial services firms. It makes mobile apps, web platforms, cloud systems, and digital products that need a secure user experience.
Zudu stays with a project from discovery and design through development and maintenance. It suits organizations building customer-facing banking tools.
Key Facts
- Best for: Financial businesses creating digital products
- Core services: Custom software, mobile applications, cloud development
- Specialization: Digital platforms and applications
- Location: UK
- Notable strength: Product-focused development approach
Contact Information
- Website: zudu.co.uk
- Email: ku.oc.uduz@tcatnoc
- Address: Clockwise, Commercial Quay, 84 Commercial St, Leith, Edinburgh EH6 6LX
- LinkedIn: www.linkedin.com/company/zudu
- Instagram: www.instagram.com/zuduofficial
12. Waracle
Waracle builds digital products for regulated industries, including financial services. It makes mobile apps, customer platforms, connected systems, and other software built around the user.
Waracle brings product strategy, UX design, engineering, and cloud development together. Its clients are businesses in financial and other regulated markets.
Key Facts
- Best for: Companies building customer-focused financial products
- Core services: Mobile apps, digital platforms, software engineering
- Specialization: Digital product development
- Location: UK
- Notable strength: Experience with regulated industries
Contact Information
- Website: waracle.com
- Email: moc.elcaraw@gnitekram
- Phone: 0330 808 4436
- Address: 7 Harp Lane, London, EC3R 6DP
- LinkedIn: www.linkedin.com/company/waracle
- Facebook: www.facebook.com/waracle
- Twitter: x.com/WaracleUK
- Instagram: www.instagram.com/waracle
13. CGI
CGI offers software engineering and technology consulting to financial organizations. It helps banks and large companies deliver software, move to the cloud, build data platforms, and run technology transformations.
Its teams work on complex systems that must stay reliable, secure, and maintainable for years.
Key Facts
- Best for: Large financial organisations requiring engineering expertise
- Core services: Software development, cloud, data, consulting
- Specialization: Enterprise technology delivery
- Location: London, UK
- Notable strength: Experience with large-scale software projects
Contact Information
- Website: www.cgi.com
- Phone: +44 (0)20 7637 9111
- Address: 14th Floor, 20 Fenchurch Street, London, EC3M 3BY
- LinkedIn: www.linkedin.com/company/cgi
- Facebook: www.facebook.com/cgigroup
- Twitter: x.com/cgi_global
Conclusion
Banking software development projects require a balance between financial expertise, secure engineering practices, and the ability to connect new products with existing systems. Companies in this list cover different needs, from building digital banking applications and payment platforms to modernising complex banking infrastructure. The right choice depends on the project scope, regulatory requirements, technology environment, and level of development support required.