ERP for construction firms: software for UK contractors

Choosing an ERP for construction is different from choosing one for a shop or a factory. Your revenue arrives through valuations and applications for payment, your costs are spread across packages, labour, plant and subcontractors, and your margin is decided long before the final account. A good construction ERP keeps all of that on one set of figures. A poor fit leaves the commercial team working in spreadsheets beside it.

This page sets out what a construction ERP should cover, which of the ERP covered by this site suit contractors and on what conditions, and the questions to put to an integrator before you commit. If you are new to the subject, start with our guide on what an ERP is.

What makes ERP for construction different

Most ERP products were designed around goods: you buy, stock, make and sell. A contractor sells a service delivered over time on a site that changes weekly. Three differences matter in practice:

• The job is the unit of control. Every cost and every pound of income must land on a contract, a section and a cost code.
• Income follows valuations, not deliveries. Revenue is recognised as work is certified, with retentions held back.
• A large share of cost is bought in. Subcontract packages, hired plant and agency labour all need orders, approvals and tax treatment of their own.

When you read a demonstration, check that these three ideas are native to the product rather than bolted on.

Estimating and tendering

Estimating is where margin is set. The ERP does not have to replace a specialist estimating tool, but it must receive the result cleanly.

What the ERP should cover

• A cost breakdown that converts an accepted tender into a budget by cost code.
• Revisions, so that variations and re-tenders do not overwrite the original baseline.
• A link between the tender price and the contract, so you can compare margin at award with margin at completion.

Which ERP can do it, and on what conditions

Odoo is modular and can be configured around quotations and project budgets, but contracting-specific estimating usually needs customisation or add-on modules. Microsoft Dynamics 365 Business Central offers job and project features in its standard product, which can be extended by industry add-ons. Oracle NetSuite handles projects and budgets within a broader cloud suite. Sage and SAP Business One can also support project-based work, generally through the integrator's configuration or add-ons.

Questions for the integrator

• Does the budget import from our estimating tool, and who maintains that link?
• How are tender revisions and risk allowances held?

Quantities, measurement and bills

Measured quantities underpin both valuations and cost reporting. In a construction ERP the bill of quantities, schedule of rates or lump-sum breakdown should be held against the contract, so each valuation refers to the same lines.

The condition to check is granularity. If the system only holds one total per contract, your quantity surveyors will keep their own workbook, and the ERP will lag behind reality. Ask to see a contract loaded with a realistic number of bill lines, and ask how a re-measure or a variation is recorded and approved.

Site operations and job costing

Job costing is the core of any ERP for a contractor. Costs reach the job from several directions: purchase orders, supplier invoices, timesheets, plant charges and subcontract payments. The system should show, per job and per cost code, the budget, the committed cost, the cost to date and the forecast to complete.

Things to insist on

• Commitments. An order raised on Monday should reduce the available budget on Monday, not when the invoice arrives.
• Mobile entry. Site teams should record time, deliveries and progress from a phone or tablet, with minimal typing.
• Approval routes. Orders and invoices should follow rules your commercial team defines, with an audit trail.

Cloud deployment tends to make site data entry simpler. Our guide to cloud and on-premise ERP explains when each model fits.

Valuations, applications for payment and retentions

This is the area where generic ERP most often falls short. A contractor must produce applications for payment, respond to payment notices, track what has been certified and manage retentions on both the income and the cost side.

The conditions that apply to payment notices in the UK are procedural and strict, so ask the integrator to show how the system tracks them rather than assuming a calendar reminder is enough.

Subcontract management and CIS

Subcontracting is central for many UK contractors, so it must be handled properly in the ERP and not by a side spreadsheet.

What the ERP should cover

• Subcontract orders with scope, price, retention terms and a record of variations.
• Subcontractor valuations, with certified payments and the amount still to be paid.
• Construction Industry Scheme (CIS) handling: the subcontractor's verified status, the deduction calculated on payment, the statement issued to the subcontractor and the information needed for your monthly return.
• The domestic reverse charge for VAT where it applies to the supply, applied automatically from the tax set-up rather than by hand.
• Insurance and compliance documents, with alerts when they expire.

Because CIS and the reverse charge depend on the type of supply and the parties, the tax set-up must be reviewed with your accountant. A reliable integrator will test real subcontract examples, not just a standard purchase invoice.

Which ERP, and under what conditions

All five products can post a purchase invoice with tax deductions, but a complete subcontract workflow with valuations and retentions normally relies on configuration or an industry add-on. Business Central and Sage have long been used by UK finance teams, so local tax handling is familiar territory for their integrators; Odoo, NetSuite and SAP Business One can be adapted to the same needs, usually with more design work. Ask each integrator for a live example in the product you are considering.

Plant, equipment and materials

A contractor's plant may be owned, hired in or hired out. The ERP should therefore be able to:

• hold an asset register with maintenance and inspection schedules;
• charge plant to jobs through internal rates or external hire invoices;
• track off-hire and on-hire dates so that charges stop when the machine leaves site;
• record materials delivered to site and transferred between jobs.

Stock matters less for a contractor than for a distributor, but site stores and yards still need controls. Where materials are bought in volume for several sites, the inventory features of Odoo and SAP Business One can be a useful base. If your business also trades materials, see our page on wholesale and distribution ERP.

Labour, timesheets and payroll links

Direct labour, agency labour and self-employed operatives are treated differently for cost and for tax. The ERP should capture hours against jobs and cost codes, apply the right rate and pass the result to payroll or to the subcontract ledger.

Check what the ERP does itself and what it hands over to a separate payroll product. Many firms keep a dedicated payroll system and integrate it. That is a sound choice, provided the integration is documented and someone owns it.

Reporting and cash forecasting

Directors in construction watch cash and margin by contract. The reporting should include:

• cost-to-complete and forecast margin for each job;
• work in progress, over- and under-billing;
• cash flow that reflects payment terms, retentions and expected certification dates;
• a view by region, division or contract type.

Reports that depend on manual adjustments each month will soon lose credibility. Ask how the work in progress figures are produced and who signs them off.

Which ERP suits which type of contractor

No single product wins for every firm. As a guide:

Treat this as a starting point. The integrator's experience in your sector counts for more than the logo on the software. Our side-by-side comparisons, such as Odoo versus Business Central and NetSuite versus Business Central, explain the differences in more detail.

Questions to ask an integrator before signing

1. Which construction clients have you worked with, and can I speak to one with a similar contract mix?
2. Will you demonstrate a valuation with retentions and a variation, using our data?
3. How do you handle CIS and the domestic reverse charge, and who tests them?
4. Which parts are standard product, which are third-party add-ons, and which are bespoke?
5. How are upgrades handled once we have customisations?
6. What do you need from our commercial team, and how much of their time will it take?
7. How will you migrate open contracts, retentions and subcontract balances?

Write the answers down and compare them across providers. The guide to choosing an ERP integrator lists further checks.

Avoiding common mistakes

Construction projects fail for the same reasons as other ERP projects, with a few specific traps.

• Migrating only closed jobs. Live contracts, with their retentions and open subcontracts, are the hardest data and the most important.
• Customising before standardising. Agree the standard process first, then decide what truly needs bespoke work.
• Ignoring site teams. If entering data is slow, it will be done late or not at all.
• Forgetting the accountant. CIS, reverse charge and retention accounting need sign-off from finance before go-live.

Our articles on ERP project mistakes and ERP implementation cover how to avoid these, and the ERP requirements template gives you a structure for the brief.

How we can help

ERP Integrator is a free service. You describe your firm, your contract types and your priorities; we match you with an integrator suited to your project. We are not affiliated with any software publisher, and the integrator, not us, delivers the project. See how it works for the steps, or browse the ERP software we cover to compare products.

Software names mentioned are trademarks of their respective publishers and are referred to for information only. This site is independent and is not affiliated with any software publisher.