A known outcome for a known price.
We compile the scope, quote the complete job and do not run a meter. If the scope proves wrong, we surface it and re-quote; we do not quietly deliver less.
Ask for a fixed-price quote →Public rate card · two commercial routes
Know the deal before the work starts.
Most work has a fixed price from a written scope. Qualifying product builds can instead be paid from the revenue the product earns.
No build invoice. We earn when the product earns.
For qualifying products, the usual shape is 25–35% of revenue received, capped per product per calendar year, with a low tail above the cap. The trigger is cash received, not an accounting definition of profit. You keep the business and product IP.
See who qualifies →S1Architecture Review2 weeks fixedfixed£12,000S2Agentic-Ready Codebase Analysis1–2 weeks fixedfixed£8,000S3Depth Audit (is it actually done?)1 week fixedfixed£6,000S4Technical Due Diligence2–3 weeks fixedfixed; expedited +50%£15,000S5Spec Compile & Build Plan2 weeks fixedfixed; credited against S6 if Zero Drift builds it£10,000S6Feature-Complete Product BuildTypically 3–8 weeks per product, quoted from the build planfixed from the agreed plan or revenue sharefrom £60,000S7Technical Recovery / RefactorScoped after an architecture or codebase reviewscoped fixed price or day ratefrom £25,000 or £1,400/dayS8Verification Harness Build2–4 weeksfixed£18,000S9Fractional CTO / Architecture LeadRetainer, 4–16 days/monthday rate or monthly retainer£1,500/day; retainers £6,000 / £11,000 / £20,000 per month for 4 / 8 / 16 daysS10AI-Native Delivery Enablement2–3 weeksfixed£14,000
Payment
Fixed work: 50% on start, 50% on delivery. Retainers: monthly in advance.
Zero Drift Ltd is not currently VAT-registered; prices are as shown.