How to Manage Cash Flow in a Construction Business
More construction businesses fail from cash flow problems than from lack of work. It sounds counterintuitive – being busy but going bust – but it’s real and it’s common. You can be turning over £300,000 a year, fully booked, and run out of money to pay your subcontractors if the timing between spending and getting paid is badly managed.
This guide covers the practical systems for keeping cash flow positive.
Why Construction Cash Flow Is Uniquely Difficult
Most industries invoice after delivery and get paid reasonably promptly. Construction is different:
You spend money first – materials, plant, labour – often weeks before you invoice and months before you get paid.
Jobs are lumpy – a single large job can represent months of work. If payment is delayed, so is a significant chunk of your income.
Retentions tie up cash – on commercial work, 3-5% of each payment is held for 12+ months. This is real money sitting in someone else’s account.
Customers default – construction has some of the highest debtor default rates of any sector. Getting money out of a customer who doesn’t want to pay takes time and energy.
Seasonal variation – bad weather slows work, Christmas stops it. Income dips, but overheads continue.
The Fundamentals of Construction Cash Flow Management
1. Take deposits before you spend
A 25-30% deposit on every job means you’re collecting money before you buy materials. Never finance a customer’s materials out of your own pocket. This is the single most impactful cash flow habit.
2. Invoice immediately on completion
Every day between finishing a job and sending the invoice is a day added to when you’ll be paid. Invoice the same day or the following morning. Not the end of the week. Not when you get round to it.
3. Set short payment terms
“30 days” is standard for commercial work but unnecessarily long for most residential jobs. For domestic work, “payment on completion” or “within 7 days” is reasonable and most customers accept it.
4. Chase overdue invoices promptly
A day-one follow-up on an overdue invoice is professional, not aggressive. Most late payers just need a prompt. The longer you leave it, the harder it gets.
5. Stage payments on larger jobs
For any job taking more than a few days, build stage payments into the contract. Tie them to clear milestones:
– 25% deposit before starting
– 25% at first fix
– 25% at second fix / practical completion
– 25% balance within 7 days of completion
This keeps cash flowing through the job rather than arriving in one lump at the end.
Tools for Staying on Top of Cash Flow
A simple cash flow forecast – a spreadsheet showing money in and money out, month by month, for the next 3-6 months. Updated weekly. Non-negotiable for any business with significant overhead or multiple concurrent jobs.
Accounting software – Xero, QuickBooks or FreeAgent give you real-time visibility of what’s been invoiced, what’s been paid, and what’s outstanding. Essential for businesses above sole trader level.
Separate tax savings account – put 25-30% of every payment into a dedicated savings account. When your tax bill arrives, the money is there. Running a business with tax money mixed into your operating account is how people get into trouble.
Retentions: The Cash Flow Trap
On commercial work, retention is cash you’ve earned but can’t access. On a £200,000 contract with 5% retention, that’s £10,000 sitting with the client for 12-18 months.
How to manage retentions:
– Track them explicitly in your accounts – know exactly how much is held and when it’s due for release
– Follow up on retention release proactively – it won’t just arrive automatically
– Factor retention into your cash flow forecast – don’t plan to spend money that’s in retention
Some contracts allow you to substitute a retention bond (an insurance product) for cash retention. Worth exploring on larger projects.
When Cash Flow Gets Tight
If you see a cash flow crunch coming (your forecast shows a negative position in 6-8 weeks), act early:
Options:
– Invoice for any work completed sooner than planned
– Chase all outstanding invoices immediately
– Speak to your bank about a business overdraft or short-term facility
– Ask key suppliers for extended payment terms
– Defer non-essential expenditure
Don’t ignore the forecast. A problem visible 8 weeks out is manageable. The same problem at 2 weeks is a crisis.
Conclusion
Cash flow problems are rarely about profitability – they are about timing and systems. A profitable trades business can still fail if money is not flowing in at the right pace. The systems described above – deposits, prompt invoicing, regular follow-up – are the most reliable protection against cash flow problems. For further guidance, visit GOV.UK: managing cash flow.
Frequently Asked Questions
What is a healthy cash flow position for a construction business?
Having at least 2-3 months of operating costs as accessible cash reserve. This covers slow periods, late payments and unexpected costs without threatening the business.
How do I handle a customer who refuses to pay on completion?
Send a formal written demand specifying the amount owed, the original agreed terms, and a deadline to pay before further action. If not paid, pursue through small claims court (for amounts up to £10,000) or a commercial debt recovery service.
Should I use a business credit card for cash flow gaps?
Only if you can clear the balance monthly. Credit card interest rates (typically 20%+) make it an expensive way to finance a gap. A business overdraft or invoice finance is almost always cheaper.
How do I forecast cash flow if my jobs are irregular?
Use your pipeline as the basis. Any job that’s contracted and starting is fairly certain – include it. Jobs being tendered should be discounted by your typical win rate. Build scenarios: what if you win half of what’s in the pipeline? A quarter? That’s your downside case.
