BlackpeakCFO™ Bookkeeping & finance systems
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Hero ACMA CGMA · CIMA chartered since 2013
UK contractors and trades

You're Winning Jobs.
Are You Making Money on Them?

Your bookkeeper enters the invoices, but nobody compares job costs with the estimate. Variations never make it into the budget. Retentions sit unchased after practical completion. CIS deductions and reverse-charge VAT get coded wrongly. And you only find out a job lost money once the final account is settled. Monthly job-level reporting fixes that.

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Bookkeeping & management accounts from £295/month · Fixed price · No meetings unless you want one · ACMA CGMA

Five Finance Problems Most Growing Contractors Have

1. Job costs drift from the estimate and nobody notices until the job is done

Labour runs over, a material price moves, a subcontractor's final invoice is higher than quoted. The company P&L can still look healthy because applications for payment are going out, while one job is quietly losing money. Without job-level costing, the first sign is often the bank balance.

2. WIP is a guess, so margin fade goes unseen

A work-in-progress schedule should show where every live job stands: costs to date, amounts applied for and certified, cost to complete and forecast margin. When the forecast margin slips a little each month (margin fade), that is the early warning. Most small contractors cannot produce a WIP schedule they trust, and the bank or credit insurer asks for one at the worst moment.

3. Variations are done but not valued

Extra work gets agreed on site, the cost is incurred, but the variation never reaches the contract value or the next application. The job looks less profitable than it is, and money you are owed is never claimed.

4. Retentions are money you have earned and forgotten

A percentage of each payment is held back. Usually part is released at practical completion and the rest at the end of the defects period. Across several jobs that adds up, and without a list of release dates nobody chases it. A retentions tracker turns it back into cash.

5. CIS and the reverse charge are coded wrongly

Subcontractors not verified, deductions at the wrong rate, a late monthly CIS return, CIS suffered never reclaimed, or VAT charged on an invoice that should have used the domestic reverse charge. Each one costs time, penalties or cash, and each one is avoidable with the right set-up.

What a UK Construction Business Gets Each Month

Monthly management accounts built around jobs, not just the company total.

Job cost reports

Every live job by labour, materials, subcontractors and plant, against the estimate plus agreed variations. You can see which jobs are slipping before they finish.

WIP schedule and margin fade

Contract value, variations, costs to date, cost to complete, applied and certified amounts, and forecast margin against the margin you priced. Laid out so your bank can read it.

Retentions tracker

Every retention held, by job, with the practical completion and end-of-defects dates, so each release is invoiced and chased on time.

CIS, handled monthly

Subcontractor verification, deductions at the right rate, the monthly CIS return filed by the 19th, deduction statements issued, and CIS suffered reconciled and reclaimed.

VAT with the reverse charge

Invoice wording and VAT codes set up for the domestic reverse charge, end-user and intermediary cases identified, and quarterly MTD VAT returns that reflect it correctly.

Dashboards (optional)

Job margin, WIP, retentions and cash on one page in Power BI, Tableau or a web dashboard. A fixed build from £1,495 that Stuart builds himself, with an automated monthly refresh from £95/month.

Software: an Honest Review, Not an Implementation Pitch

Many contractors are told they need a construction ERP. Some do. Many need better job coding and reporting in the software they already pay for.

Work with what you have

Xero, QuickBooks or Sage, with tracking categories or projects set up so every cost lands on the right job.

Review before you buy

If you are weighing up a construction-specific system, you get an independent view of whether it fixes your actual problem and what moving your data would involve. Stuart does not resell or implement ERP software.

Build the reporting

Job cost reports, the WIP schedule and dashboards built from your data, so the numbers stop living in one spreadsheet that only one person understands.

Not sure where the gaps are? The fixed-price Finance Systems Audit (£1,995) looks at your job costing, month-end and reporting and gives you written findings and a roadmap. You can also try the free margin fade calculator on a live job.

Useful next steps

Tell Us How Your Jobs Are Tracked Today

Send your details and Stuart will reply by email within one business day with what he would look at first in your job costing, WIP and CIS set-up, and a fixed price.

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Or get in touch via email

Frequently Asked Questions

How do monthly job cost reports help a UK contractor? +

Each live job gets its own cost codes for labour, materials, subcontractors and plant. Every month the costs to date are compared with the original estimate plus agreed variations, and the forecast final margin is updated. You see a job drifting while it is still running, rather than at the final account when the money has already gone.

What is a WIP schedule and what is margin fade? +

A work-in-progress (WIP) schedule lists every live job with its contract value, agreed variations, costs to date, estimated cost to complete, amounts applied for and certified, and the margin you now expect to make. Margin fade is the gap between the margin you priced the job at and the margin the latest forecast shows. Watching it month by month is the earliest warning that a job is going wrong. Banks and credit insurers often ask for a WIP schedule when they review your facilities.

Can you handle CIS deductions and the monthly CIS return? +

Yes. If you pay subcontractors, you must verify them with HMRC, deduct CIS at the rate HMRC gives you (20% for registered subcontractors, 30% for unregistered, nothing for those with gross payment status), file the monthly CIS return by the 19th, pay the deductions over, and give each subcontractor a statement. If you are a subcontractor yourself, the CIS deducted from your payments needs reconciling and reclaiming: a limited company offsets it against its PAYE through payroll, and a sole trader claims it through Self Assessment.

How does the VAT domestic reverse charge affect my invoices? +

Since 1 March 2021, most supplies of construction services between VAT-registered businesses that are reported under CIS use the domestic reverse charge. The supplier invoices without charging VAT and states that the reverse charge applies; the customer accounts for the VAT on their own return. It does not apply when you invoice the end user or an intermediary supplier who has told you so in writing. Getting this wrong means invoices reissued and VAT returns corrected, so the invoice templates and VAT codes are set up correctly from the start.

Do you implement construction ERP software? +

No. Stuart has not implemented a construction ERP and does not sell implementations. What he does is work with the system you already use (often Xero, QuickBooks or Sage with a job-management add-on), give you an honest view of whether a construction-specific system is worth the cost before you buy one, and build the job cost reports, WIP schedule and dashboards from your data himself. He has moved finance functions off spreadsheets onto dedicated platforms before, so he knows what a data migration involves.

What does it cost? +

Monthly bookkeeping and management accounts start from £295/month. Dashboards are a fixed build from £1,495, with an automated monthly refresh from £95/month. If you want an outside view before committing, the fixed-price Finance Systems Audit (£1,995) reviews how your job costing, month-end and reporting work today and gives you written findings and a roadmap.

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