Who owns the WPS when a subcontractor does the welding?

The sub typically brings their own WPS and PQRs. The prime contractor or GC is responsible for verifying that the sub's documents are current, cover the work being performed, and comply with the edition of D1.1 the project specifies. Ownership of the documents stays with the sub, but responsibility for compliance rests with whoever is the contract holder.

What documents should a prime request from a welding sub?

At minimum: the WPS(s) covering each process and joint type being used, the supporting PQR(s) for each WPS, current WPQ records for all welders or WOPQs for welding operators, and the sub's qualified welder list. Some specs also require the sub's quality plan or ITP.

Can a sub use a WPS written to the 2020 edition when the project specifies 2025?

Possibly, but it requires review. Most technical requirements carried over, but Table numbers changed and several specific rules were updated. The CWI accepting the sub's WPS must confirm the procedures meet 2025 requirements even if they were written to 2020. A blanket acceptance without review creates a compliance gap.

What happens if a sub's WPS doesn't cover a joint type encountered in the field?

Work on that joint must stop until a compliant WPS is in place. Proceeding without a qualified WPS is a code violation. The sub must qualify the procedure (via PQR) or obtain a prequalified WPS that covers the joint. The prime CWI should flag this immediately rather than waiting for an audit.

Accepting a subcontractor's WPS under AWS D1.1

When a prime fab shop or GC uses a sub's welding procedures, these are the documents to request, the checks a CWI must run, and where shops get caught on audit.

When a prime fabricator or general contractor subcontracts structural welding work, two welding procedure documents arrive on the same job site: the prime's QC plan and the sub's welding procedures. The sub brings their own WPS and PQRs, their own welders, and often their own inspection setup. The prime CWI is responsible for verifying that what the sub brought actually meets the project specification — and that responsibility doesn't disappear just because the sub has a thick folder of paper.

Failures here are not hypothetical. Third-party audits and owner inspections routinely flag projects where a sub's WPS was accepted without verification, only to reveal that the procedure didn't cover the joint thickness actually being welded, cited the wrong edition of D1.1, or had a PQR with mechanical test results that didn't meet current acceptance criteria.

Who is responsible for what

AWS D1.1 places the qualification obligation on the contractor or fabricator doing the work. The sub, as the party making the welds, is responsible for having a compliant WPS and qualified welders. But the prime contractor is responsible for the work scope they contracted out — which means they cannot accept the sub's work without verifying the sub's documents.

The structural drawings and project specification define which edition of D1.1 governs. The prime CWI must confirm that the sub's WPS and PQRs comply with that edition. If the project specifies AWS D1.1:2025 and the sub submits procedures written to the 2020 edition, the CWI must evaluate whether the procedures meet 2025 requirements — not simply whether they comply with their stated edition. Several technical rules changed between editions, including Table numbering for essential variables and specific row-level requirements in what is now Table 6.6. See AWS D1.1:2025 vs 2020: what changed for a focused diff.

The responsibility question for WPS authorship — who writes it, who stamps it — is separate from who performs the work. See WPS responsibility: fabricator, contractor, and EOR for the general framework.

The document package to request from a sub

Before a sub's crew starts making structural welds, request and review:

1. WPS for each process and joint type The sub should provide a WPS for every welding process and joint configuration they will use. A sub doing SMAW on groove joints and FCAW-G on fillet welds needs two procedures — one for each process — unless a single WPS explicitly covers both. The WPS must specify process, filler metal, base metal group, position(s), preheat requirements, and all other essential variables per AWS D1.1 Table 6.6.

2. Supporting PQR(s) for each WPS Every WPS must be backed by at least one PQR — unless it is a prequalified WPS meeting all conditions of Clause 4 of AWS D1.1. For each PQR, verify:

Mechanical test results (tensile, bend) meet D1.1 acceptance criteria
The test was witnessed by a CWI (name and signature on the PQR)
The base metal and filler metal tested are consistent with what the WPS specifies for the project
Thickness and position of the test coupon support the production parameters

For more on reading a PQR test report, see how to read a PQR test report.

3. Current WPQ or WOPQ records for all welders/operators Request a qualified welder list with current WPQ records for every person the sub intends to deploy. Confirm:

Each WPQ covers the process and position(s) the welder will use in production
The continuity record shows the welder has used the process within the prior 6 months (AWS D1.1 Clause 6.4.1)
The WPQ is signed by a CWI

A common gap is a sub who provides a welder list but not the underlying WPQ forms. The list is not a qualification record — the signed, witnessed WPQ is the record.

4. Quality plan or inspection and test plan (if required by spec) Some owner specifications and AISC-certified shop requirements require the sub to submit a quality plan describing their internal inspection process. At minimum, understand who on the sub's crew is responsible for visual inspection and NDE witness, and whether they have a CWI.

Specific flags to check on the WPS

When reviewing a sub's WPS documents, common deficiencies include:

Edition mismatch: The WPS cites "Table 6.5" for essential variables, indicating it was written to the 2020 edition (where the main essential variable table was 6.5, not 6.6 as in 2025). This is not automatically a disqualifier — the substance may comply — but it requires explicit review, not a rubber stamp.

Process mode ambiguity: The WPS says "FCAW" without specifying self-shielded (FCAW-S) or gas-shielded (FCAW-G). These are different processes under D1.1, with different filler metal classifications and shielding requirements. If the WPS doesn't specify, it can't be verified.

Thickness range not covering production joints: A PQR run on 5/8-inch plate may not cover the 1-1/2-inch flanges the sub will actually be welding. Pull the test plate thickness from the PQR and check the D1.1 qualification range. Don't assume the sub verified this themselves.

Missing preheat on the WPS: If the sub's WPS omits preheat, or lists a value lower than D1.1 requires for the base metal and carbon equivalent, the CWI must flag it before welding starts. Preheat underspecification is an essential variable finding. The carbon equivalent and preheat requirement overview is a useful reference for checking whether a listed preheat is plausible.

Expired or unverified welder qualifications: A qualification card from a training center is not a WPQ. Welders must be qualified to AWS D1.1 by a CWI-witnessed test on the applicable process and position — or by documentation of prior qualification on the same process with continuity evidence.

What the prime CWI documents

The prime CWI's acceptance of a sub's WPS should be documented, not verbal. A written review record — noting which WPS and PQR numbers were reviewed, any discrepancies found and how they were resolved, and the CWI's conclusion that the documents are acceptable — creates an audit trail. If the job later faces a third-party audit, that review record demonstrates due diligence.

If any document is missing or has a deficiency, the deficiency should be recorded in writing and the sub notified. Work covered by that WPS should not proceed until the deficiency is resolved.

For a broader CWI audit workflow, see CWI WPS review checklist and common WPS deficiencies found in third-party audits.

Maintaining the sub's records in the project file

The prime should retain copies of the sub's WPS, PQRs, and qualified welder list as part of the project record. If the owner or structural engineer of record requests documentation of all welding on the project, the prime needs to produce both their own documents and the sub's.

This is especially true on AISC-certified projects, where the certification audit may ask to see the complete welder qualification record set — not just the prime's — for work performed within the certification scope.

Tracking sub qualifications in the same system as prime qualifications simplifies that document production significantly. See how the WPS platform handles multi-crew qualification records and audit-packet export.

Rule library based on AWS D1.1:2025; verify against your governing edition.