Every payroll run produces a SHA-256 locked, timestamped audit pack. Not a payslip. A complete compliance record — sealed, immutable, and ready the moment HMRC or a tribunal asks for it.
Most payroll produces a payslip. bookd. produces evidence. The Audit Shield is the name for what gets built automatically on every single run — a complete, timestamped, integrity-locked record of every compliance decision made.
If HMRC opens an enquiry, if a worker brings a tribunal claim, if a supply chain audit is triggered — the file is already built. You don't go looking for documents. You export the pack.
SHA-256 hashing means the record cannot be altered after sealing. Every pack carries a unique hash — if a single byte changes, the hash changes with it. That's what makes it admissible evidence, not just a saved spreadsheet.
In sequence, automatically, without anyone asking for it. This is the bookd. engine at work on every single payroll run.
Every worker's employment and CIS status is checked against HMRC before the run proceeds. Status, deduction rate, and verification timestamp are recorded. No assumptions carried over from previous runs.
Live HMRC verificationFor variable-hours workers, the 52-week rolling average is computed. For fixed-hours workers, statutory entitlement is applied. The method used is recorded per worker. No flat-rating.
FWA compliantHourly rate cross-referenced against current National Minimum Wage thresholds. Pass/fail recorded with hours worked and rate applied. A kill-switch prevents submission if NMW is breached.
Automatic kill-switchTax, National Insurance, CIS deductions, employer contributions — all calculated and recorded to the penny. Each figure carries the calculation basis and timestamp.
Penny-accurateThe complete compliance record is assembled into a structured audit pack. SHA-256 hashing is applied. The pack is now immutable — any change to any field invalidates the hash. The record is permanent.
Tamper-evident · ImmutableThe Full Payment Submission is sent to HMRC only after human sign-off. Every submission is logged with operator ID, timestamp, and HMRC acknowledgement reference. Nothing is filed automatically without approval.
Human sign-off requiredThe Audit Shield protects every client type — the specific risk it addresses is different for each one.
JSL supply chain evidence. If unpaid tax liability travels up to you, the audit pack is your defence.
Agency protection →PI exposure reduction. White-label the Audit Shield to your clients — compliance becomes your strongest service line.
Partner programme →FWA enforcement protection. Rolling average documented correctly for every variable-hours worker, every run.
Hospitality compliance →IR35 and status evidence. Director salary and dividend decisions recorded with reasoning and HMRC status.
PSC payroll →Full CIS verification chain. Subcontractor status, deduction rate, and verification evidenced per worker per run.
CIS compliance →Book a free 20-minute audit call. Mark will map your exact risk position and tell you what protection you need.
Book a free call →Free 20-minute call. No obligation. Mark will assess your current setup and tell you exactly what the Audit Shield would close for you.