Geographic coverage
We work with partners operating across London, the South East and wider UK regions. Your application should clearly state the areas you can mobilise to and any programme constraints.
Subcontract for Mainline
Become a Delivery Partner
Subcontract for Mainline Groundworks. Join our approved network of commercial groundworks, civils and specialist subcontractors for future project opportunities.
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- Commercial subcontract opportunities
- Regional delivery
- Long-term relationships
Why subcontract for Mainline
We work with approved subcontractors on commercial developments, principal contractor packages and regional civils work across the UK. Subcontracting with us means structured scope, clear programmes and long-term relationships.
Commercial developments
Work alongside Mainline on mixed-use, commercial and developer-led schemes across the UK.
Principal contractor packages
Structured subcontract packages with clear scope, programme interfaces and reporting requirements.
Regional work
Opportunities matched to your geographic coverage — London, South East and wider UK regions.
Structured introductions
Approved delivery partners are introduced to relevant packages based on trade, capability and coverage.
Future framework opportunities
Long-term relationships with the potential for repeat work and framework-style engagement.
Working with Mainline across service categories
Mainline coordinates groundworks and civils packages across multiple trades — excavation, foundations, piling, drainage, earthworks, roads and sewers, and enabling works. Delivery partners may be introduced to packages that match their trade, geographic coverage and commercial experience.
Expected standards
Baseline insurance, RAMS capability and verifiable commercial experience are required. We do not operate a formal accreditation scheme — applications are reviewed against the requirements listed below.
How to express interest
Complete the application form below with your company details, trades, coverage areas and experience summary. Approved partners may be introduced to relevant packages — we do not guarantee work volume. Submitting also creates a free contractor leads account so you can sign in and browse marketplace opportunities.
Public directory
Groundworks companies can also appear in the Mainline contractor directory. Claiming a profile is separate from the delivery partner application.
Who we're looking for
Specialist subcontractors and civils delivery partners across the commercial construction supply chain.
- Groundworks contractors
- RC frame specialists
- Drainage contractors
- Earthworks
- Piling
- Utilities
- Section 278
- Section 104
- Reinforced concrete
- Civils
Requirements
Baseline standards for delivery partners working on commercial groundworks and civils packages.
Insurance
Public liability and employer's liability cover with appropriate limits for commercial work.
Health & Safety
RAMS capability, CSCS where required, and a consistent approach to site controls and induction.
Relevant experience
Verifiable commercial or developer-led delivery with references and project history.
Geographic coverage
Defined operating areas with the ability to mobilise to agreed programmes.
Plant / capabilities
Appropriate plant, supervision and operatives for the packages you deliver.
Contractors, subcontractors and suppliers can use our confidential reporting route to raise serious concerns relating to safety, conduct, fraud, harassment, environmental issues or unethical behaviour.
Subcontract for Mainline
Apply to join the delivery network
Apply to subcontract for Mainline Groundworks. Submit your company details and we will review your application for inclusion in our approved subcontractor network for future project opportunities.
- Subcontract for Mainline on commercial groundworks, civils and infrastructure packages
- Structured subcontract scope with clear programme interfaces and reporting
- Regional work matched to your trade, capability and coverage
- Long-term subcontracting relationships and future framework opportunities
We review every subcontractor application against insurance, health & safety, experience and coverage before adding you to the network.