SNT-TC-1A Compliance for Inspection Service Providers

Any US inspection service provider whose customer, code or purchase order invokes SNT-TC-1A: weld and fabrication NDT under ASME BPVC Section V and Section VIII, structural work under AWS D1. Personnel are qualified under employer-based certification, so a contracted Level III can sign the written practice and administer examinations for the firm.

1, refinery, piping and tank work under the API inspection codes, and pipeline construction where 49 CFR 192.243 requires NDT performed to written procedures by trained, qualified persons. It binds the firm's qualification programme, not the individual technician. SNT-TC-1A is a recommended practice, not law. It gives an employer the framework for qualifying and certifying its own NDT personnel. For an inspection service provider the deliverable is a Written Practice covering training, examination, experience, vision and recertification for every method and level the firm sells, reviewed and approved by the employer's NDT Level III and retained on file for audit. Customers then audit the firm against its own Written Practice rather than against the standard directly. The 2024 edition adds the ASNT 9712 Program to the recognised examination routes, restricts eye drops used to improve vision, tells employers to assess whether externally referenced examinations meet their requirements, and expects written-examination proctors to be trained.

Source: ASNT Recommended Practice No. SNT-TC-1A (2024), with Addendum — ASNT product listing (source.asnt.org) and ASNT standards page (asnt.org/standards-publications/standards); the addendum took effect May 2025 and ASNT recommends use with ANSI/ASNT CP-105 (2024). ASNT 'Ten Key Shalls of SNT-TC-1A' and 'What to Do in an Audit' (asnt.org blog). ASNT Employer-Based Certification Accreditation Program, certification.asnt.org — audit stages, three-year validity and published audit fees (single site and multi-site up to 150 technicians US$5,300; 151–500 technicians US$6,150; 500+ by quote), checked August 2026. 49 CFR 192.243(a)–(b) quoted from the govinfo CFR text. ASME Section V Article 1 T-120 and Section VIII Div. 1 UW-54 taken from secondary technical summaries, not read from the code; treat the clause designations as indicative. Vision examination frequency deliberately not stated as a number here — it was not verified against the 2024 text.

SNT-TC-1A at a glance — authority, scope and what it demands
Item	What applies	Why it matters
Authority	American Society for Nondestructive Testing (ASNT) publishes it. Nobody enforces SNT-TC-1A directly — it becomes binding when a code, customer or regulator invokes it (ASME BPVC Section V and Section VIII, AWS D1.1, the API inspection codes, prime purchase orders). ASNT Certification Services LLC will audit and accredit a firm's programme against it through the Employer-Based Certification (EBC) Accreditation Program.	The body that issues, audits and can withdraw
Applies to	Any US inspection service provider whose customer, code or purchase order invokes SNT-TC-1A: weld and fabrication NDT under ASME BPVC Section V.	Whether this binds your firm at all
Personnel certification	Employer-based — the firm certifies its own, under a qualified Level III	Decides whether an outsourced Level III can sign for you
Renewal	Recertification is periodic and the interval is fixed by the employer's own Written Practice, not by ASNT. ASNT describes a recommended maximum interval of five years between renewals for NDT personnel. Recertification requires evidence of continued competence — re-examination or documented continuing activity — plus current vision records. Accreditation of the programme itself under the ASNT EBC route runs three years, with some registrations on one-year terms requiring annual surveillance.	Diarise from the certificate date, not from memory
Methods in scope	UT, PAUT, TOFD, RT, CR/DR, MT	Each method needs its own procedure and qualified personnel
Industries	Oil and gas, Refining and petrochemical, Power generation, Pipeline construction, Structural steel fabrication and construction	Where this regime shows up in contracts

Who does SNT-TC-1A apply to?

Any US inspection service provider whose customer, code or purchase order invokes SNT-TC-1A: weld and fabrication NDT under ASME BPVC Section V and Section VIII, structural work under AWS D1.1, refinery, piping and tank work under the API inspection codes, and pipeline construction where 49 CFR 192.243 requires NDT performed to written procedures by trained, qualified persons. It binds the firm's qualification programme, not the individual technician.

Can an outsourced Level III sign for SNT-TC-1A compliance?

Yes. SNT-TC-1A accepts employer-based certification, which places the obligation on the employer and allows a contracted Level III to write and sign the written practice, approve procedures and administer examinations. The Level III must be qualified in each method they sign for, and the employer still owns the records.

What documents does a SNT-TC-1A audit ask for?

Written Practice for the control and administration of NDT personnel training, examination and certification, approved by the employer's NDT Level III and retained on file, NDT Level III qualification records — ASNT NDT Level III certificates, or the outside-agency Level III agreement plus that person's credentials, Training records showing classroom hours per method and level against the SNT-TC-1A training table, with content traceable to ANSI/ASNT CP-105 topical outlines, Documented on-the-job experience with dates, method, and supervisor attestation, General, specific and practical examination records, graded answer sheets, and the Level III-approved examination question bank. Auditors open records before they open manuals, because a manual describes intent while records show practice. The most common failure is a documented system that does not match what the technicians actually do.

How often is SNT-TC-1A renewed?

Recertification is periodic and the interval is fixed by the employer's own Written Practice, not by ASNT. ASNT describes a recommended maximum interval of five years between renewals for NDT personnel. Recertification requires evidence of continued competence — re-examination or documented continuing activity — plus current vision records. Accreditation of the programme itself under the ASNT EBC route runs three years, with some registrations on one-year terms requiring annual surveillance. Firms that diarise renewal from the certificate date rather than from the last audit avoid the lapse that forces a full reapplication.

What are the most common SNT-TC-1A findings?

Written Practice is a copy of the standard rather than a description of how the firm actually trains, examines and certifies, Examination question bank not approved by the NDT Level III, or reused without control, Certification examination administered by the candidate, or by someone the candidate supervises, On-the-job experience recorded without traceable dates, methods or supervisor attestation. These recur because they are records problems rather than capability problems — the work is being done correctly and the evidence is not being kept.

Which NDT methods does SNT-TC-1A cover?

UT, PAUT, TOFD, RT, CR/DR, MT, PT, VT. Each method in scope needs its own approved procedure and personnel qualified in that specific method; a Level III qualified in ultrasonics cannot sign for radiography.

Personnel certification under SNT-TC-1A

Employer-based. The employer — not ASNT, not a third party — issues the certificate, and ASNT is explicit that where the person holds no third-party certification the credential is revoked on termination of employment. Because SNT-TC-1A states that in no case shall a certification examination be administered by oneself or by a subordinate, and because the Written Practice must be approved by an NDT Level III, a firm with no Level III on staff routinely engages an outside agency Level III. That contracted Level III can write and approve the Written Practice, build and grade examinations and recommend certification; the employer still signs and issues the certificate.

The audit sequence

Eligibility check and application to ASNT's Employer-Based Certification (EBC) Accreditation Program, submitting the signed application and payment, the Written Practice, the full list of locations seeking accreditation, the roster of NDT-certified technicians and backup certification documentation
Desktop audit: a qualified auditor reviews the Written Practice against SNT-TC-1A; the firm has 30 days to respond to nonconformances and a further 30 days to implement corrections
Compliance audit, conducted remotely, of actual certification packages against the firm's own Written Practice; 30 days to respond and 60 days to implement corrective action (an on-site audit is available at additional travel cost)
Panel review by a three-person independent panel confirming all accreditation requirements are satisfied
Accreditation decision — certificate valid three years and listing on the ASNT EBC registry
Renewal through the same audit sequence; ASNT notifies at least 90 days before expiry, and some registrations carry one-year terms with annual surveillance

Documents an auditor asks for

Written Practice for the control and administration of NDT personnel training, examination and certification, approved by the employer's NDT Level III and retained on file
NDT Level III qualification records — ASNT NDT Level III certificates, or the outside-agency Level III agreement plus that person's credentials
Training records showing classroom hours per method and level against the SNT-TC-1A training table, with content traceable to ANSI/ASNT CP-105 topical outlines
Documented on-the-job experience with dates, method, and supervisor attestation
General, specific and practical examination records, graded answer sheets, and the Level III-approved examination question bank
Vision examination records — near-vision acuity and colour contrast differentiation
Individual certification and recertification records stating method, level, technique and effective dates
Evidence that outside training or examination services used by the employer were assessed against the Written Practice
Calibration records for equipment the examinations and inspections depend on (light meters, gauges, reference standards)

Findings firms get against SNT-TC-1A

Written Practice is a copy of the standard rather than a description of how the firm actually trains, examines and certifies
Examination question bank not approved by the NDT Level III, or reused without control
Certification examination administered by the candidate, or by someone the candidate supervises
On-the-job experience recorded without traceable dates, methods or supervisor attestation
Certificates issued without stating method, technique, level and scope limits
Vision examination records expired or missing, with no mechanism that stops the technician working
Outside training provider or outside examination service used with no employer assessment against the Written Practice
Level III oversight not evidenced — auditors write the finding against the Level III as well as the technician
Firm audits itself against a different edition of SNT-TC-1A than the one its purchase order names