The Six Weeks Between Finishing a Commercial Electrical Job and Getting Paid For It

A commercial electrical contractor's engineer finishes the last fix on a Friday afternoon. The installation is complete, tested to their satisfaction on a preliminary basis, and working to specification. From a physical standpoint, the job is done. But payment won't arrive for another six weeks at the most optimistic estimate - and often considerably longer. For electrical contractors doing significant commercial work, this gap between finishing the job and receiving cash for it is structural. Most businesses absorb it without tracking exactly why it happens or how many weeks each stage actually accounts for. The numbers, once you look at them, tell a consistent story.

Why Finishing the Work Doesn't Mean You Can Invoice

On a commercial project, the physical installation being complete is rarely what triggers the final invoice. What triggers it is the Electrical Installation Certificate - the document that confirms the work has been designed, installed, inspected, and tested in line with BS 7671. Without that certificate, most commercial clients and main contractors won't authorize a final payment. This is not unusual: a common position among clients is that no certificate means no final payment, treating the EIC as the formal proof of completion that makes the invoice legitimate.

The EIC can only be issued after testing is complete. And testing creates its own dependencies on a commercial project. The space needs to be accessible and sufficiently complete for proper verification. On a multi-trade fit-out, that means other contractors have to have cleared the same areas. If the floor isn't down, if the ceiling tiles aren't in, if the joinery isn't finished, or if the fire alarm system is still being commissioned in the same zones - the electrical contractor's ability to run proper test sequences and document results gets pushed back.

Main contractors control that sequencing. An electrical contractor working as a sub-contractor has no direct authority over when other trades finish their work. They can flag delays and request access windows, but they cannot force the conditions that allow testing to proceed. In practice, this typically means a gap of one to two weeks between the point when an electrical contractor considers their installation complete and the point when they can properly conduct testing, issue the certificate, and raise the final invoice.

The Commercial Payment Timeline in Numbers

Once the EIC is issued and the final invoice goes out, the payment terms clock starts. Standard commercial terms are 30 days. The actual average payment time is different. Research into electrical contractor businesses puts the average for commercial work at 52 days from invoice - 22 days beyond agreed terms. This is not a figure driven by disputed invoices or non-paying clients. It represents the typical, unremarkable payment behavior of commercial customers and property management firms on agreed 30-day terms.

On an annual revenue of £700,000 with 40% coming from commercial work, that 22-day average delay means approximately £17,000 sitting permanently outside the business at any point in the year. Not in a single overdue invoice - distributed across a portfolio of commercial jobs, each one landing 22 days later than the agreed date. For a business trying to fund the next job's materials from the last job's receipts, that standing gap has a real cost.

The broader construction sector context makes the picture sharper still. Construction carries the worst average payment delays of any UK industry, running 38.2 days beyond agreed terms. For electrical contractors working under a main contractor, the problem can compound further: payment typically flows down the supply chain only after the main contractor has received payment from the client, adding a further layer of timing uncertainty on top of the agreed commercial terms.

Stack the full sequence together: one to two weeks waiting for site conditions that allow proper testing, a few days to complete verification and issue the certificate, then 52 days from invoice to actual payment receipt. A job that was physically finished on day one generates cash somewhere around week nine.

Where the Gap Gets Longer Without Active Management

The structural portion of this gap - the testing dependency, the commercial payment terms - is not easy to eliminate. But a meaningful part of what pushes the nine-week estimate toward twelve or thirteen weeks is administrative: jobs sitting in an informal category of "nearly done" that nobody actively tracks.

An electrical contractor running eight to twelve live commercial jobs at different stages has a certification and invoicing backlog that only surfaces when someone specifically asks for it. Which jobs have outstanding certificates? Which jobs have certificates but no invoice raised? Which invoices are past due with no follow-up? Without systematic tracking of each job through the full sequence from installation completion to payment receipt, answering those questions requires manual investigation every time someone thinks to ask.

The practical consequences accumulate in predictable ways. Testing is ready to proceed on a job but nobody schedules a return visit because the job is nominally still "on site." A certificate comes back from the engineer on a Thursday but the invoice isn't raised until the following Tuesday because the office didn't know it had arrived. An invoice goes out with the wrong calculation of when payment is due because someone assumed terms ran from the invoice date when the contract specifies from the EIC date. Each of these delays adds days that have nothing to do with client behavior or contractual terms - they come from a workflow that treats the certification and invoicing cycle as background administration rather than a billable milestone to be managed.

What Matters Most Before the Payment Reforms Take Effect

The UK government confirmed in March 2026 that it intends to introduce statutory interest of 8% above the Bank of England base rate on overdue commercial invoices, alongside a mandatory 60-day payment cap for large firms paying smaller suppliers. For electrical contractors working on commercial projects, these are the most significant changes to payment law in over 25 years.

Those tools work only when the invoice is clean and arrives on time. Statutory interest accrues from the day after payment is due - but it only counts from the date the invoice was submitted. A certificate issued late, or an invoice raised a week after the certificate, or an application that goes out without the right documentation attached, delays the start date for both the payment terms and any interest claim. The reforms strengthen the contractor's position at the back end of the payment cycle. Getting the front end right - certificate out promptly, invoice raised immediately, documentation attached - is what makes that stronger position usable.

The six-week gap between finishing a commercial electrical job and receiving payment is not entirely within an electrical contractor's control. But the administrative portion - which often accounts for two to three weeks of it - is. Treating certification and invoicing as a live management discipline rather than a back-office function is where most of the recoverable weeks sit.

• Operational Efficiency for Electrical ContractorsFlow Efficiency · accessed 2026-06-30
• UK Construction Retention Ban 2026: Contractor GuideIntoAEC · accessed 2026-06-30
• Electrical Contractor Debt Recovery UKHays Collections · accessed 2026-06-30

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