Costs and margins
Cost is not a pricing input for this product. The platform costs about £161 a month fixed and 1.6p (recommended login policy) to 8.5p (today's policy) per worker per month variable, against prices of £1.30–£3.19 per worker. The one cost decision that matters is how often you send an SMS code.
- Fixed platform cost: £160.65 a month (£1,928 a year) with a proper database and monitoring, up to about 3,000 workersS5, S6, S23. About £255 a month above that.
- A UK phone verification costs 8.3p ($0.05 Verify fee plus one UK SMS segment at $0.056, at $1 = £0.78)S1, S2. Verified monthly, that is 8.3p per worker per month: five times everything else in the variable line put together. Verified only on a new device, it is 1.4p per worker per month.
- Everything else is rounding: translating a 300-word post into six languages costs 0.5pS4; Mux captions are free and 100,000 delivery minutes a month are freeS3.
- Margin on the variable line is above 98% at any price. Counting the £161 fixed platform as cost of goods too, margin is 49–79% with 250 workers on the platform, 86–94% at 1,000 and 95–98% at 5,000 (table below).
- One Site customer (£180 a month) covers the fixed platform cost. At the £1.80 Site rate that is about 90 enrolled workers.
The one product decision that decides the cost line
| Login policy | Verifications / worker / year | £ / worker / month | Variable cost at 1,000 workers / month | Verdict |
|---|---|---|---|---|
| A. Verify every login, monthly (as the app does today with 30-day sessions) | 12 | £0.083 | £86 (£83 verification + £3 everything else) | Do not ship |
| B. Device-bound session, re-verify every 90 days | 4 | £0.028 | £31 | Acceptable |
| C. Device-bound session; re-verify only on a new device, cleared storage, or a 180-day gap | ≈2 | £0.014 | £17 | Recommended |
| D. As C, own one-time codes over plain SMS (drop Twilio Verify) | ≈2 | £0.007 | £10 | Saves 47% of message cost; you lose Verify's SMS-pumping fraud protection. Revisit above ~50,000 verifications a year. |
Do this in the product before the first paying customer: long-lived device-bound sessions with re-verification only on a new device. It is simultaneously the cheapest option and the best experience: a site operative should never be asked for a code to read a safety briefing.
If a customer insists on SMS delivery of posts (some will, on sites with no wifi), that is 4.4p per message per worker: eight posts a month to 500 workers is £176 of pass-through against a £950 subscription, 19% of revenue gone. Every plan includes an allowance of two critical-SMS posts per worker per month (worst case 4.4% of a full band's revenue); excess SMS is priced at 8p a message on the order form. Push is free, which is why "does it work without an app?" is the demo's most important 30 seconds.
Fixed platform cost, per month
| Line | Up to ~3,000 workers | ~3,000–15,000 workers | Source |
|---|---|---|---|
| Laravel Forge (Growth) | £13.99 | £13.99 | S6 |
| EC2 t4g.large, web/app, London | £40.42 | £80.84 (×2) | S5 |
| EC2 t4g.medium, queue + Reverb + Redis | £20.21 | £20.21 | S5 |
| EBS gp3 disks | £6.85 (est) | £10.31 (est) | S5 |
| RDS MySQL db.t4g.medium | £38.70 (single-AZ) | £77.93 (multi-AZ) | S23 |
| RDS storage + backups | £8.83 (est) | £8.83 (est) | S23 |
| S3 + CloudFront | £3.68 | £14.72 | S5 |
| Error monitoring | £14.72 | £14.72 | S23 |
| Uptime monitoring | £11.04 | £11.04 | S23 |
| Email (SES), domain, DNS | £2.21 | £2.21 | S23 |
| Total fixed | £160.65 | £254.80 | USD lines at 0.78 (S7) |
Today TeamTalk runs MySQL on the same box as the app, which is about £45 a month cheaper than RDS. The table prices the setup you should be on before a plc customer asks about backups and point-in-time recovery, because they will.
Variable cost per worker per month
AssumptionsS20: 8 posts a month, 3 languages per site, 20% of posts with a 2-minute video, push for everything, verification policy C (about two verifications per worker per year).
| Driver | Unit price | Pence / worker / month | Source |
|---|---|---|---|
| Phone verification (policy C) | $0.05 + one UK SMS segment at $0.056 = $0.106 ≈ 8.3p per verification, ≈ 2 a year | 1.4 | S1, S2 |
| Translation | $0.20 / $1.20 per 1M tokens in / out; 0.5p per post into six languages, shared by the site | 0.02 | S4 |
| Video encoding | $0.025 per minute, once per video (Mux Plus tier, 720p; Basic-tier encoding is free) | 0.1 | S3 |
| Video storage | $0.0024 per minute per month | 0.1 | S3 |
| Video delivery and captions | Free to 100,000 minutes a month; captions free | 0 | S3 |
| Push notifications, realtime | Free (web push; self-hosted Reverb) | 0 | — |
| Photo storage and egress | S3 + CloudFront at list price (the 12-month free tier is not counted) | 0.1 | S5 |
| Total variable, policy C | ≈ 1.6p | ||
| Total variable if you keep verifying monthly (policy A) | ≈ 8.5p | ||
| Add SMS delivery of 8 posts a month | + 35p | S2 | |
Cost per worker by platform size
Gross margin at list prices
| Workers on platform | All-in cost / worker (fixed ÷ workers + policy C variable) | at £1.30 (top band, full) | at £1.80 (Site, full) | at £2.20 (≤250 band, full) | at £3.19 (501 band floor) |
|---|---|---|---|---|---|
| 250 | £0.66 | 49% | 63% | 70% | 79% |
| 1,000 | £0.18 | 86% | 90% | 92% | 94% |
| 5,000 | £0.07 | 95% | 96% | 97% | 98% |
Calculator
Unit prices in the calculator: verification 8.3p (S1, S2), SMS 4.4p (S2), Mux encoding $0.025 and one month of storage $0.0024 per minute (S3), translation and storage as above, USD at 0.78 (S7).
What it costs to run the business for a year (not the product)
| Line | £, 12 months | Note |
|---|---|---|
| Infrastructure (fixed platform) | 1,930 | £160.65 × 12 |
| Twilio verification + fallback SMS | 400 | Depends entirely on the login policy above |
| OpenAI, Mux, S3/CloudFront | 150 | Negligible at this scale |
| Domains, DNS, Google Workspace | 250 | Monitoring, uptime and SES are already inside the fixed platform line above; not counted twice |
| Cyber Essentials + ICO fee + Companies House | 490 | CE £320 + VAT; ICO £52; confirmation statement £50S8, S9 |
| Insurance (PI, PL, cyber) | 1,200 | Estimate: PL and PI £300–£900, cyber adds £300–£500; get three quotesS10 |
| Legal: contract + DPA review | 1,500 | Once, before customer oneS11 |
| Accountant | 1,500 | |
| Sales tooling (LinkedIn Sales Navigator, HubSpot free, email) | 1,300 | Sales Navigator is the big line |
| Travel to sites and offices | 2,500 | This sector does not buy over Zoom alone |
| Two demo handsets and contracts | 700 | The demo needs a real phone |
| Collateral and case-study design | 800 | |
| Pen test (month 8), Cyber Essentials Plus | 5,500 | Estimates; defer both until a named deal is gated on them in writing |
| Non-salary total | 18,220 (12,720 with the last line deferred) | |
| Founder living costs | 30,000–45,000 | The real number |
| Cash needed for 12 months | ≈ 43,000–58,000 | Base-case cash collected in year one is about £34k (Chapter 5), so the gap is £9k–£24k. Plan for £45k–£60k of runwayS17, S25. |
The business is not capital-intensive: infrastructure is under £200 a month and margin on the variable line is above 98%. The entire cash requirement is your time and the length of UK construction procurement. Do not spend on ISO 27001 or Cyber Essentials Plus until a specific deal is gated on it in writing.