Software for UK commercial electricians
Last commercial GC withheld 5% retention on a £42k job for 12 months. Found out about it the same week the VAT was due.
Commercial sparky work is a different business. The tickets are £5k-£50k+ instead of £350. The terms are 30-60 days instead of same-day card. The VAT is reverse-charge under CIS, not the normal flow. Retention sits on the GC’s books for six to twelve months after you’ve finished. You’re running subbies and CIS deductions, daysheets and labour logs, and the bookkeeping software you bought when you were a one-van sparky doesn’t know what any of it means.
This page is for the sparkies who left domestic behind - fit-outs, industrial refits, school rewires, healthcare estate, retail rollouts. If you’re still mostly domestic with the occasional commercial bolt-on, the main electricians page is a better fit; if you’re CIS-only, the builders page and the construction page are sibling reads.
What your week actually looks like
- Three jobs running concurrently, each with a different GC’s preferred paperwork.
- CIS reverse-charge invoices Xero almost gets right, except the contractor / sub-contractor flag is wrong on one in five.
- Retention release that requires you to chase a quantity surveyor twelve months after sign-off.
- A subbie whose CIS verification you’ve done three times this year because the deduction rate keeps changing.
- Daysheets on WhatsApp that get reconciled into Excel at the weekend.
- CDM-15 notification on the bigger sites - your principal-contractor relationship, the F10, the health-and-safety file.
- Variations that get verbally agreed on site and then disputed at the agreed-measure stage.
- A commercial EICR for a school where the cert format is bespoke to the local authority and changes every year.
The shape is project-based, not job-based. Most sparky software is built for the job. That’s the gap.
Example problems we could solve
1. CIS reverse-charge built into the invoice flow - properly
The “almost right” moment: Xero’s CIS handling is almost right. QuickBooks is almost right. FreeAgent doesn’t really do it. The “almost” is what trips you.
Solved looks like: a CIS layer that sits between your job data and your books. For every contractor-to-contractor invoice it applies the reverse-charge VAT logic correctly (notification on the invoice, no output VAT, contractor accounts for input + output), records the gross / deductible / net split, applies the verified deduction rate for that subbie, and pushes the right entries through to Xero or QuickBooks. Generic Zapier-style flows can’t do this; CIS needs purpose-built logic per the HMRC spec. We build it once, then it just works - plus a CSV export ready for the CIS300 monthly return.
2. The retention ledger
The “I forgot it was there” moment: retention sits on five different GCs’ books, totalling £18k, and you only remember it when the bank balance gets tight.
Solved looks like: retention as a first-class object in your books. Every commercial invoice with a retention clause raises two rows: the cash due now, and the retention due at release date (typically 6 or 12 months post-PC). The ledger shows you what’s outstanding by GC, what’s due to be released next quarter, what’s overdue, and chases the quantity surveyor automatically when release is past due. Same chase-ladder shape as the hub’s letting-agent flow, tuned for commercial terms - more polite, longer cadence, escalates to a phone call before email. Plus a year-end view your accountant will actually thank you for.
3. Subbie + CIS verification flow
The “new subbie on Tuesday” moment: HMRC CIS verification call to make, deduction rate to record, UTR to store, insurance details to chase, payslip to issue, payment to make.
Solved looks like: a one-page subbie onboarding flow. UTR + NI + insurance + bank details captured in a structured form they fill in on their phone; HMRC CIS verification triggered; deduction rate stored; the WhatsApp daysheet template wired up. Daysheets come in through WhatsApp; hours log to the job; a payslip PDF generates with CIS deduction applied; payment runs go out through Telleroo or straight to the bank. The whole subbie lifecycle in one flow instead of five spreadsheets.
4. Daysheet → labour log → job-cost dashboard
The Monday-morning moment: you don’t actually know whether last week’s job was profitable.
Solved looks like: a thin layer that turns WhatsApp daysheets and material receipts into a per-job cost picture. Every labour-hour attributed to a job; every CEF / Edmundson / Rexel delivery allocated against a job from the supplier PO ref; variations tracked separately so they don’t get swallowed by the base contract figure. End of the week, the dashboard shows you margin per job, hours-vs-quote variance, and which jobs are running over before they finish, not after. Doesn’t replace your accounts; sits in front of them. Same shape as the dashboard we built for pharmaceutical-analytics.com.
5. The variation log GCs will sign
The agreed-measure moment: verbal variation on Tuesday, disputed at agreed-measure in October.
Solved looks like: an in-the-van variation log. Each variation captured on site (photo, description, scope delta, hours estimate, materials estimate, the GC contact who agreed it), emailed to the contact with a one-click sign link, recorded as agreed on response. By the time you get to agreed-measure, you’ve got a signed trail per variation. Doesn’t change the commercial relationship; just makes the dispute go away because the variation was agreed on the day, in writing, by the person who agreed it.
6. CDM-15 site pack - for when you’re principal contractor
The “F10 in their format” moment: F10, construction phase plan, health-and-safety file. Each GC wants it in their format.
Solved looks like: a CDM-15 site pack template - F10 submission, construction phase plan, RAMS, asbestos register reference, H&S file structure, weekly toolbox-talk record. Generated per site from a template; updated as the site progresses; the H&S file at handover comes out of the same store. Where the GC has a specific format, we template theirs alongside the generic one. Not legal advice - your CDM duty stays with you - but the document production stops being a Sunday job.
The closest things we’ve already built
- pharmaceutical-analytics.coma dashboard we built for an analytics consultancy. The job-cost dashboard in problem 4 is the same shape: operational data in, weekly view out. See Pharmaceutical Analytics.
- MMI Servicesthe insurance-claims system we’ve been modernising. CIS-shaped logic and retention-style cashflow are familiar territory; the take over a legacy system and modernise it pattern transfers when the commercial sparky already has Sage / Pegasus / Eque2 in place.
- HC Electricalthe electrician we built and run software for in Haverhill. Domestic-first reference, but proves the same studio runs production sparky infrastructure. See Hc Electrical.
A named commercial-sparky case study isn’t yet in the portfolio. When one lands and clears permission, it’ll appear here.
FAQ
Will this replace Sage / Pegasus / Eque2 / SimPro / Joblogic?
Usually no. The commercial-sparky software stack is heavier than the domestic one and the cost of ripping it out rarely pays back. We sit on top, replace the bits that hurt (CIS, retention, daysheets, variation log), and leave the bits that work. If you’re on Tradify or paper-and-WhatsApp scaled up beyond what it was meant for, that’s a different conversation.
Can you handle CIS300 monthly returns?
We generate the CSV in the right shape; you (or your accountant) file it. The HMRC CIS portal isn’t somewhere we’ll be clicking submit for you - the indemnity sits with the contractor.
What about CDM principal-designer responsibilities?
Out of scope for the software - that’s a competency-and-process question, not a tool one. We can build the document set; the duty still sits with whoever’s holding the role.
What does it cost?
Sized to your business - depends on subbie count, retention ledger size, whether you want the CDM pack, whether the job-cost dashboard pulls from your existing accounts. We talk it through, agree price in writing. See pricing.
How does this play with my accountant?
Best case: your accountant ends up with cleaner data and the year-end gets easier. We design the CIS and retention flows alongside the accountant so the entries match what they expect. Most accountants are happy to be in the room for the scoping call.
Up to the hub
← UK electricians (main page) · EICR specialist → · EV installer → · Builders → · Construction →
Tell us about the projects you’ve got running
How many concurrent jobs, how many subbies, what the retention book looks like, what bookkeeping you’re on. Send an enquiry - we’ll come back with a sketch.