Software for UK commercial fit-out builders

Strip-out Monday. RAMS Tuesday. F10 Wednesday. Retention released next December.

Commercial fit-out is a different business. The customer isn’t a homeowner - it’s a commercial tenant, a main contractor’s QS, or an FM commissioner running a panel of three fit-out firms across a portfolio. The project is a 4-16 week fit-out of an office, a retail unit, a restaurant, a clinic, a small healthcare suite, a light-industrial conversion. CDM 2015 applies on every job - principal designer, principal contractor, the F10 notification to HSE when the project tips past >30 working days with >20 workers simultaneously or >500 person-days. RAMS / method statements travel with the trades; the construction phase plan is the gate to site; the fire risk assessment is its own document and the H&S file at handover is half the deliverable. Retention is 5-10% held at practical completion + half released 6 months later + the rest at the end of the 12-month defects-liability period - that’s £4k-£12k held back on a £100k fit-out. Reverse-charge VAT applies on every commercial sub-contract invoice at the line level. The cash cycle is 30-60 days against PAYE wages on Friday.

This page is for builders whose week is mostly commercial fit-out. If commercial is one part of a mixed week alongside £40k domestic extensions, the main builders page is the better fit; if your business is mostly domestic extensions and refurbs, the extension-specialist spoke is the sibling. Commercial fit-out is its own thing because the cash cycle, the paperwork, and the customer-side stakeholder are all different from a domestic project - the contract is JCT or NEC-shaped, the interim valuation is agreed-measure, the customer is somebody whose Tuesday-morning email is “can I have the H&S file extracts and the BS 7671 certs from the M&E by Friday”, and the retention is the bit that gets forgotten by both sides until you remind the QS.

What your week actually looks like

• A £85k restaurant fit-out for a Mayfair tenant - week 3 of 8, the architect’s contract administrator wants the RAMS for the strip-out, the fire risk assessment, and the F10 notification before the next-Tuesday site visit.
• CDM 2015 principal-contractor obligations on the same job - the construction phase plan, the RAMS per trade, the welfare facilities, the H&S file at handover all live with you.
• An interim valuation with the main contractor on agreed-measure - 30-day terms, 5% retention deducted, reverse-charge VAT line worded the way HMRC and the main contractor’s bookkeeper both recognise, supporting daysheets attached.
• A snag-list at practical completion the FM commissioner wants on a single PDF with photos by Friday - and the work-in-progress photos from the M&E and the shopfit subs spread across three phones in two formats.
• Retention release on the fit-out from last October - half came in May, the other half is due next November, and you’ve nearly forgotten the project.
• A 24-hour Public Liability + Employer’s Liability cert chase from a new commercial commissioner who won’t put you on the panel until the £10m PL cover and the £5m EL are evidenced, alongside the CHAS / SafeContractor / Constructionline current-membership certificates.
• The fire-strategy document the building-control officer wants alongside the Part B sign-off on the restaurant fit-out - the architect’s drafted it, the fire engineer’s signed it, you’re the one assembling it into the H&S file.
• The mechanical and electrical sub-contractor’s first interim invoice with CIS reverse-charge applied - your bookkeeper queries it, the M&E firm’s bookkeeper queries it back, you’re on a phone call you didn’t need to be on.
• A retention-bond conversation with the main contractor’s QS - he wants a bond instead of cash retention; your bank’s been on holiday for three weeks.
• An asbestos register check on a 1970s office before the strip-out - the building owner’s HSG264 R&D survey is somewhere on the agent’s Drive and the strip-out is booked for Monday.
• A daysheets reconciliation on Friday - three subbie trades, four working days, the labour-only lines and the labour-and-materials lines that have to split correctly to keep the CIS treatment right against this month’s CIS300.

Example problems we could solve

1. CDM 2015 + RAMS + F10 + the construction phase plan, generated per project

The architect’s-CA moment: “Mayfair restaurant fit-out. Architect’s contract administrator wants the RAMS for the strip-out, the F10 notification, and the fire risk assessment before Tuesday’s site visit. My last RAMS was three years ago in a Word doc I’ve lost.”

Solved looks like: every commercial project has a structured CDM file from day one. Project profile (location, project type, planned duration, planned person-days) auto-evaluates whether F10 notification to HSE is required (the >30 working days with >20 workers simultaneously, or >500 person-days thresholds); the F10 form pre-fills and you submit. The construction phase plan template generates per project from a CDM 2015 checklist - site rules, welfare facilities, emergency procedures, traffic management, asbestos register reference, contractor list. RAMS / method statements generate per trade per phase from a template library - strip-out (working at height, dust, manual handling, electrical isolation), demolition (asbestos awareness, structural integrity), M&E (LV electrical, water isolation, hot-works permits), kitchen install (gas commissioning, fire-suppression), shopfit (glazing, signage). Each RAMS auto-attaches to the sub-contractor’s WhatsApp when they’re booked. The H&S file assembles as the project runs, not on Friday before PC. The CDM-15 paperwork is the gate to commercial work - without it, the architect’s CA won’t sign the interim, the FM commissioner won’t pay; the file lives or dies on day one of the project. The longer version lives at Compliance Evidence Record.

2. Reverse-charge VAT interim valuations on agreed-measure, in the wording the QS recognises

The bookkeeper-query moment: “M&E sub-contractor’s first interim came in with reverse-charge VAT applied. My bookkeeper queries it, the M&E firm’s bookkeeper queries it back. Third time this quarter and I’m on a phone call I didn’t need to be on.”

Solved looks like: an interim-and-final valuation engine that bakes reverse-charge VAT logic at the line level, not the invoice level. Per commercial customer (main contractor or direct tenant), the engine stores their VAT number, their CIS verification status, the project reference, the contract administrator’s name, the retention percentage, the agreed terms, the contract form (JCT Minor Works / JCT Intermediate / NEC ECC short, whichever you tend to write). Each interim valuation lands as a single PDF with the work-package breakdown on agreed-measure, the labour-and-materials split, daysheets attached as supporting evidence, the retention line itemised, the reverse-charge VAT line worded the way HMRC and your main contractor’s bookkeeper both recognise. Xero rules push the same record to the books with the right CIS + reverse-charge treatment automatically. The “my bookkeeper doesn’t recognise this” delay is a communication problem, not a software bug - the build is shaped around making the invoice harder to misread than to accept. Same engine as the commercial plumber spoke and the commercial electrician spoke - different trade, same wording discipline. The longer version lives at Multi Channel VAT & CIS Invoicing.

3. Retention release tracker - first half + second half, twelve months apart

The forgotten-by-November moment: “Practical completion was October last year. Half of retention released at PC; the other half is due at end-of-defects-liability twelve months on. By the time the date rolls round I’ve forgotten the project.”

Solved looks like: retention as a tracked object that doesn’t go to sleep. On every commercial contract, the retention percentage, the practical-completion date, the first-half release date (typically at PC), the end-of-defects-liability date (twelve months on), and the second-half release date go into the record. Each release date triggers a friendly chase to the customer’s QS 30 days before - “the second half of retention on the Mayfair fit-out is due on the 14th; here’s the snag-list sign-off and the as-built drawings from PC, plus the H&S file extracts the architect’s CA already signed” - with escalation if it slips. Retention-bond alternative tracking alongside where the customer accepted a bond instead of cash retention; the chase ladder differs (bond release goes to the bond issuer; cash release goes to the customer’s QS); both surface on the same dashboard so neither slips. Retention is the bit that legally should be released but practically gets forgotten by the customer’s QS until you remind them; the system reminds them in your voice with the evidence attached, so the conversation is short. Shape-wise the same chassis as the recurring-recall annuity on the trade hubs - historical record becomes the workflow trigger months or years later. The longer version lives at Stage Payment & Retention Ledger.

4. The interim valuation + snag-list + H&S file handover pack, assembled as you go

The FM-commissioner moment: “FM commissioner at the Mayfair restaurant wants the snag-list, the as-built drawings, the O&M manuals, the H&S file, the fire-strategy sign-off, and the part-completion certs by Friday. I’ve got it all, just not in one place - the M&E certs are in the sub’s email, the kitchen O&M is in a PDF on the kitchen-fitter’s phone, the asbestos register reference is on the agent’s Drive.”

Solved looks like: every project closes through a structured handover pack flow. Interim valuations (per the contract’s monthly or staged cycle) generate from the work-completed-to-date snapshot - labour, materials, plant, preliminaries, daysheets evidence, retention deducted - as a single PDF for the customer’s QS. The snag-list workflow runs on the tablet at PC walk-round - each item captured with a photo, the room, the trade tag, the type; items auto-route to the responsible trade via WhatsApp; sign-off photo closes the item; items that aren’t yours flag clearly so the conversation about whose snag happens once with photo evidence, not three times. The H&S file at handover assembles automatically - the construction phase plan, the RAMS by trade, the F10 acknowledgement, the principal-contractor designations, the asbestos register reference, the fire risk assessment, the BS 7671 electrical installation certs from the M&E sub, the Gas Safe + commercial CP certs from the gas engineer, the FENSA / CERTASS window cert, the O&M manuals from the kitchen / HVAC / signage suppliers. The FM commissioner gets one PDF with everything in it. The FM commissioner’s “I want everything by Friday” is the gate to the final retention release, and the build is shaped around the pack being assembled-as-you-go, not assembled-on-Friday. The longer version lives at Customer & Third Party Portal.

5. Subbie verification, daysheets, CIS300 - the commercial-side spine

The Friday-afternoon-daysheets moment: “Three subbie trades on the Mayfair fit-out this week - strip-out crew Monday-Tuesday, M&E Wednesday-Thursday, kitchen-fitter Friday. Daysheets in three formats, two of them on WhatsApp voice-notes, one on a folded A4 in the cab. The CIS deduction has to be right against the M&E firm’s labour-only lines and right against the kitchen-fitter’s labour-and-materials lines, and the CIS300’s due in three weeks.”

Solved looks like: the CIS spine, tuned for the commercial-sub-contracting weight. New subbie firm added → HMRC CIS verification queue with the UTR + VAT number; deduction rate (gross, 20%, 30%) stored against the firm with the verification reference. Daysheets land via WhatsApp through the week from every subbie crew on every site, normalised against the project’s agreed labour rates; the labour-only vs labour-and-materials split is captured at line level so the reverse-charge VAT and the CIS treatment both come out right on the interim valuation that lands the following Monday. CIS300 monthly return assembles on the 5th with every subbie firm’s deductions calculated per line, ready for review and submission before the 19th. Subbie payslips PDF, bank-payments CSV, Xero handoff to keep the books right. The commercial-side CIS load is heavier than the domestic side because every interim invoice is a CIS event, not just the monthly payroll - the engine is shaped around that. The longer version lives at Multi Channel VAT & CIS Invoicing.

The closest things we’ve already built

• HC Electricaldifferent trade, same Suffolk trade-chassis with the CIS-aware commercial-sub flow on the electrical side. The closest live reference for how the same reverse-charge VAT invoicing + retention tracking pattern runs in a Suffolk trade business, and the chassis a builder version sits on. (Named pull-quote and final outcome figures hold until the permission checklist clears - see Hc Electrical.)
• mendbuddythe multi-channel AI agent platform behind the inbound triage and the FM-commissioner / architect-CA-side comms cadence on a long fit-out. Trained on your contract forms, your subbie list and your interim-valuation language. See Mendbuddy.
• MMI servicesa legacy insurance-claims surface (Plesk PHP) we took over and are quietly modernising. Useful proof we can take over and modernise older internal systems - relevant when the main contractor already runs Procore / Aconex / 4Projects / Asite and the work has to live alongside it rather than replace it. See Mmi Services.

FAQ

Up to the hub

← UK builders (main page) · Extension specialist (sibling) → · Commercial plumber (adjacent trade) → · Commercial electrician (adjacent trade) → · Commercial-catering gas engineer (adjacent trade) → · Commercial-maintenance roofer (adjacent trade) →

Tell us about the commercial side

What main contractors you work with, what FM commissioners are on the book, what the retention exposure looks like today, where the CDM paperwork sits. Send an enquiry - we’ll sketch what we’d build.