How to choose a third-party inspection company.
Third-party inspection proposals are unusually hard to compare. Scope is described in inspector-days, rates look similar, and every provider claims global coverage and qualified inspectors. The differences that actually decide whether defects get caught — inspector competency evidence, reporting turnaround, escalation authority and independence — are usually invisible until the first hold point.
The decisive criteria are not price and coverage. They are whether the provider will name the inspectors and show their qualification records, how fast reports arrive, whether the inspector holds documented stop-work authority, and whether the provider has a commercial relationship with the vendor being inspected.
This guide gives a selection scorecard, an RFQ question checklist you can paste into a tender, the red flags worth disqualifying on, and a plain comparison of third-party inspection against building the same capability in-house.
- 01Compare inspector competency evidence, not headcount or claimed global coverage.
- 02Ask for the actual named inspector and their certification records before award.
- 03Independence is disqualifying when broken: the TPI must have no commercial tie to the vendor.
- 04Reporting turnaround belongs in the contract — 24 hours for NCRs, 48 for routine visits.
- 05Scope by hold points and deliverables, not by inspector-days, or you buy attendance instead of assurance.
The seven criteria that actually differentiate providers
Almost every proposal will satisfy the first two. Providers separate sharply on the remaining five.
Inspector competency evidence
Not 'certified inspectors' in the brochure — the named individual's CSWIP/AWS CWI/API/NDT Level II certificates, expiry dates and relevant equipment experience, provided before award.
Genuine independence
No ownership, agency or referral relationship with the vendor being inspected, and no other contract with that vendor. Ask for it in writing.
Documented stop-work authority
The inspection agreement must state when the inspector can halt production, the escalation path and who ratifies the hold. Without it you have an observer.
Reporting turnaround and format
Same-day notification of any non-conformance, a report within 48 hours, and photographic evidence indexed against the ITP line item — not a narrative email.
Real local presence
Ask which office the inspector actually flies from. 'Global network' often means a subcontracted local agency you never meet and cannot audit.
Scope written as hold points
A proposal priced in inspector-days without a marked-up ITP is a proposal to be present, not to verify anything specific.
Accreditation where it is required
ISO/IEC 17020 accreditation matters where a code, insurer or regulator demands it. Where it does not, do not pay a premium for a certificate that has no bearing on your scope.
Data-book and turnover support
Ask how inspection records arrive: indexed and traceable to the ITP, or as loose PDFs your team re-sorts at handover.
The RFQ question checklist
Paste these into your enquiry. The quality of the answers separates providers faster than any rate comparison.
Reasons to disqualify a bidder
- Refuses to name inspectors before award, or names them and then substitutes silently.
- Holds any other commercial contract with the vendor being inspected.
- Prices only in inspector-days with no reference to your ITP or hold points.
- Cannot state a contractual reporting turnaround.
- Reports arrive as 'observed, satisfactory' with no measurement, criterion or photograph.
- Presents accreditation for an inspection type unrelated to your scope as if it covers it.
- Will not accept stop-work authority language in the agreement.
Third-party inspection versus in-house QA
| Consideration | Third-party inspection | In-house QA team |
|---|---|---|
| Cost profile | Variable — pay per visit or campaign, no cost between projects | Fixed — salaried regardless of workload peaks and troughs |
| Independence | Structurally independent of the vendor and of your schedule pressure | Reports internally, so release pressure is harder to resist |
| Geographic reach | Inspector local to the fabricator; no long-haul travel per visit | Travel cost and lost days for every overseas vendor |
| Discipline coverage | Welding, coatings, NDT, electrical and rotating specialists on call | Limited to the disciplines you employ |
| Retained knowledge | Provider knows the code; you own the records | Knowledge of your standards and vendors compounds over time |
| Best fit | Multi-vendor, multi-region or peak-load scopes; anything needing demonstrable independence | Steady, single-site work with predictable volume |
See how we scope inspection and quality oversight
We scope surveillance by hold point and deliverable, name the inspector before award, and hand over records indexed to your ITP.
How to compare rate cards fairly
Headline day rates are the least useful number in an inspection proposal. Normalise every bid to the same basis before comparing: a day rate that excludes travel time, mobilisation, waiting time and report writing will land 30–50% above its quoted figure once invoiced.
Ask each bidder to price the same worked example — for instance, three hold points at one fabricator 200 km from their office, including one visit aborted because the vendor was not ready. That single scenario exposes travel policy, waiting-time charges, abort fees and minimum-day rules more reliably than any rate table.
- Day rate: is it portal-to-portal or on-site hours only?
- Travel: charged at full rate, half rate, or included within a radius?
- Waiting time and aborted visits: who carries the cost when the vendor is not ready?
- Report writing: included in the day, or billed separately?
- Minimum engagement: half-day, full-day, or a multi-day minimum per mobilisation?
- Out-of-hours and weekend loading, which matters when hold points fall on a night shift.
Verifying the choice after award
- Step 01
Check the first three reports hard
Every finding should cite a clause, a measurement and a photograph. If the first reports are narrative, correct it immediately — the standard set in week one persists to turnover.
- Step 02
Confirm the named inspector attended
Cross-check the report signature and certificate number against the person named in the bid. Silent substitution is the most common post-award failure.
- Step 03
Test the escalation path once, deliberately
Raise a low-stakes query and see how fast it reaches a decision-maker. Discovering the escalation path is broken during a genuine stop-work is expensive.
- Step 04
Audit the provider annually on long campaigns
A short second-party audit of the inspection provider — competency records, report quality, independence declarations — keeps performance from drifting across a multi-year programme.
Auditing an inspection provider or supplier
Our external audit team runs second-party audits of inspection providers, fabricators and suppliers against your specification and ISO 9001.
Questions we get on this topic
What should I look for in a third-party inspection company?
Named inspectors with verifiable certification records, genuine independence from the vendor being inspected, documented stop-work authority, contractual reporting turnaround, and a scope written against your hold points rather than priced in inspector-days.
Does a third-party inspection company need ISO/IEC 17020 accreditation?
Only where your specification, insurer, regulator or the applicable code requires it. Where it is not required, accreditation is a useful signal of process discipline but should not outweigh inspector competency and independence for your specific scope.
Is third-party inspection cheaper than an in-house QA team?
For multi-vendor, multi-region or peak-load work, usually yes — you pay per visit rather than carrying salaries between projects, and you avoid long-haul travel to overseas fabricators. For steady single-site volume, an in-house team is often cheaper and retains knowledge of your standards.
What questions should be in an inspection RFQ?
Ask who the named inspector is, their relationship with the vendor, whether they will hold written stop-work authority, contractual report turnaround, whether they will mark up your ITP before award, whether the inspector is an employee or subcontractor, and how records are delivered at turnover.
How do I compare inspection day rates fairly?
Normalise them. Ask every bidder to price the same worked scenario including travel, waiting time and one aborted visit, and confirm whether the rate is portal-to-portal, whether report writing is included, and what the minimum engagement is.
What is the biggest mistake owners make when selecting an inspection provider?
Buying inspector-days instead of verified hold points. Attendance without a written acceptance criterion and stop-work authority produces reports that say 'observed, satisfactory' and non-conformances that surface at turnover.
Comparing inspection providers?
We are happy to review your ITP and inspection scope before you go to tender — including where third-party inspection is genuinely worth deploying and where it is not.