ISO 9001 with ISO 14001, 45001, or 27001: integrated cost
ISO 9001 (quality), 14001 (environmental), 45001 (occupational health and safety) and 27001 (information security) all share the Annex SL high-level structure and roughly 60 to 65 percent of clause requirements overlap. Integrated management systems exploit this. The saving is real but is often misquoted.
Worked Year-1 cost on a 50-person reference firm
Quality and environmental
Shared clauses 4, 5, 6, 7, 9, 10. Internal audit programme runs once across both standards. Stage 1 + 2 audit days partially shared (combined audit typically 5 days vs 6.5 standalone for a 50-person firm).
Sector fit: Manufacturers, contractors with environmental obligations, larger services firms.
The classic IMS
Three standards share Annex SL high-level structure. Internal audit and management review run once across all three. Combined audit typically 6 to 7 days vs 9 to 10 standalone for a 50-person firm.
Sector fit: Construction, manufacturing, facilities, contractors. PQQ-driven demand often requires all three.
Quality and information security
Lower saving than 9001+14001 because ISO 27001 has a dedicated control set (Annex A) that does not overlap with ISO 9001. Internal audit and management review can integrate; control evidence cannot.
Sector fit: IT services, software, managed services, fintech.
The cost-side breakdown for ISO 27001 on its own is on iso27001certificationcost.com.
Larger combinations: where the curve flattens
A four-standard IMS (9001 + 14001 + 45001 + 27001 or similar) is a different operational beast. The saving on the combined audit fee stops scaling proportionally; the implementation complexity for SMEs starts to dominate. For most sub-100 employee firms, two or three standards is the practical limit. Four-plus is for organisations with dedicated quality, environment, and information security functions.
Three conditions for the integrated discount
01Same certification body across all standards. Cross-body integration is rare and inefficient because audit teams cannot combine days across bodies.
02Same surveillance schedule. Multi-standard surveillance audits run together on a single visit; staggered surveillance produces no saving.
03Internal audit programme genuinely integrated, not just relabelled. A single audit covering quality, environment, and safety topics is integrated; three sequential audits with the same auditor are not.
Where the "save 40 percent" marketing falls down
The 40 percent headline assumes a from-scratch, all-at-once implementation under a single body. This is the maximum saving case and applies to roughly 30 percent of multi-standard buyers we see in the UK.
Adding a second standard in Year 2 to an existing single-standard QMS produces a smaller saving. The original audit days are not shared retrospectively, and the first standard's surveillance schedule may not align with the second standard's certification cycle. Realistic saving on the second-standard increment is 10 to 20 percent, not 40.
Adding a second standard at recertification (Year 4) restores most of the original saving, because the recertification audit can be combined cleanly. If you are planning a second standard within 18 months of first certification, time it to the recertification cycle if possible.
Integrated management systems beyond ISO standards
Integrated management systems pairing ISO 9001 with ITIL service-management practices share governance overheads but not audit days, since ITIL has no certification body audit. The training-and-certification cost for ITIL practitioner certifications is broken down at itilcertificationcost.com. Manufacturers commonly bundle ISO 9001 with ISO 14001 (environmental management), which shares roughly half the documented procedures and most of the internal audit programme.