ONAC Audit Preparation for Inspection Companies
A ONAC audit runs in 6 stages, beginning with submit the application and scope to onac; onac applies its application-review procedure.. Organismo Nacional de Acreditación de Colombia (ONAC) as the national accreditation body; Ministerio de Minas y Energía and the Agencia Nacional de Hidrocarburos (ANH) for the regulated hydrocarbon inspection scopes tests the system by sampling finished work backwards to the records behind it, so preparation means reconciling.
ONAC is the Colombian state's accreditation body and its inspection body scheme, coded OIN, is where NDT sits. Scopes are granted against ISO/IEC 17020:2012 under inspection field code 22, "Equipos y elementos a través de ensayos no destructivos — END", and the annexed scope names the exact activity, the execution criteria and the acceptance and rejection criteria down to the clause and table, plus the inspection body type A, B or C. Two hydrocarbon inspection scopes have been made effectively compulsory by regulation: flare efficiency measurement and natural gas leak detection and quantification at production facilities, under Ministerio de Minas y Energía Resolución 40066 de 2022 as modified by Resolución 40317 de 2023, and ANH Resolución 10981 de 2023. What separates firms that clear an audit from firms that collect findings is not the quality of the documentation but whether it describes what actually happens.
Source: ONAC accreditation certificate 24-OIN-053 for ATP Integridad y Corrosión S.A.S, NIT 900.412.013-9, ISO/IEC 17020:2012, form FR 3.5.3-03 V7 approved 2023-07-18, read in full: inspection field code 22 for NDT (ultrasonic, visual-dimensional and MFL of drill pipe, heavy weight, drill collar, casing and tubing, and visual inspection of storage tanks) as a type C body, and inspection field code 29 for flare efficiency and gas leak detection as a type A body, with dates 2025-07-28, 2026-07-10 and 2028-07-27, and citing DS-1 Drill Stem Inspection Vol. 3 5th ed. 2020, ASME BPVC.V-2023 Art 23 SE-797, API Spec 5CT 11th ed. December 2023, API RP 5C1 8th ed. 2020 and API Std 653 5th ed.; ONAC OIN and OCP scheme pages and the DOA directory (accessed August 2026), noting 26 inspection categories; ONAC Reglas del Servicio de Acreditación RAC-3.0-01 version 12, 8 January 2025, for the month 9/21/33/45 surveillance and month 55 re-evaluation schedule; Ministerio de Minas y Energía Resolución 40066 of 11 February 2022 and Resolución 40317 of 10 April 2023; ANH Resolución 10981 of 31 October 2023 and ANH Circular No. 0003 of 30 January 2025. ACOSEND's ONAC ISO/IEC 17024 accreditation for NDT Levels I and II to ISO 9712:2012 is reported by secondary sources only and should be re-verified in ONAC's DOA before it is relied on. No public Ecopetrol NDT personnel specification was verified, so none is quoted.
| Stage | What happens | What it tests |
|---|---|---|
| Stage 1 | Submit the application and scope to ONAC; ONAC applies its application-review procedure and confirms scheme, scope and fee from the. | Where the paperwork is tested against itself |
| Stage 2 | Documentary evaluation against ISO/IEC 17020:2012 and the applicable ONAC accreditation rules in the RAC series | Where the paperwork is tested against practice |
| Stage 3 | On-site evaluation plus witnessing of inspections for every activity, method and normative document in the requested scope | Where the paperwork is tested against practice |
| Stage 4 | Non-conformity treatment with evidence of corrective action within the timescale ONAC sets | Where the paperwork is tested against practice |
| Stage 5 | Decision by ONAC's decision-making body and publication of the certificate and annexed scope in the Directorio Oficial de Acreditados; the. | Where the paperwork is tested against practice |
| Stage 6 | Surveillance evaluations at months 9, 21, 33 and 45 after approval of the renewal, with re-evaluation at month 55 | Where the paperwork is tested against practice |
| Renewal | ONAC does not run one fixed validity across every scheme; the certificate itself carries the expiry date, and it is the surveillance rhythm that is published. Under the accreditation service rules RAC-3.0-01, version 12 dated 8 January 2025, from the first renewal onwards ONAC schedules surveillance evaluations in months 9, 21, 33 and 45 after approval of the renewal, with re-evaluation in month 55, and the new cycle begins from publication of the certificate in the DOA. A live example: certificate 24-OIN-053 carries a grant date of 28 July 2025 and an expiry of 27 July 2028. | Diarised from the certificate date, not the last audit |
How long does ONAC audit preparation take?
Document work — the written practice, procedures and quality manual — takes weeks. What cannot be compressed is documented experience and records history: on-the-job hours accrue in real time, and calibration and certification history cannot be back-filled. Firms that start when the audit is scheduled rather than announced clear it without findings.
What does Organismo Nacional de Acreditación de Colombia (ONAC) as the national accreditation body; Ministerio de Minas y Energía and the Agencia Nacional de Hidrocarburos (ANH) for the regulated hydrocarbon inspection scopes look at first?
Records, not manuals. A manual states intent; records show practice. The usual opening move is to take a completed job and trace it back to the technician's certification, the instrument's calibration, the approved procedure and the report — and see whether all four reconcile.
What are the most common ONAC findings?
Scope creep: the firm inspects a tubular size or applies a normative document that is not in the annexed scope, so the report cannot legitimately carry the accreditation mark, The internal procedure version named in the ONAC annex has been superseded internally without notifying ONAC of the change, Acceptance criteria applied from a different edition than the annex names; DS-1 Volume 3, 5th edition 2020, clause 3.6.5 and tables 3.6.1, 3.6.2 and 3.11.2 are specific, and an older edition's tables are a finding, A type C inspection body performing work that, as contracted, makes it supplier or repairer of the item inspected, breaking the declared impartiality arrangement. Almost all of them are evidence problems rather than capability problems: the work was done correctly and the proof was not kept, or was kept somewhere the firm could not retrieve during the audit.
Can a consultant attend the ONAC audit?
Yes, and it changes the outcome. Someone who has sat through the same audit at other firms answers in the auditor's own terms, produces the right record without a search, and stops a clarification turning into a finding. The firm still owns every answer — the consultant does not speak for it.
What happens after a ONAC finding?
A corrective action with a deadline, and evidence of closure at the next audit. Repeat findings are treated far more seriously than first ones, because they show the corrective-action system itself is not working.
Does ONAC require a pre-audit or gap assessment?
Not as a requirement, but the arithmetic favours it: a gap assessment finds the same evidence problems the auditor would, without the finding attached, and while there is still time to fix them. Firms entering their first ONAC audit blind typically collect findings that a sampling exercise would have caught.
What the auditor asks to see
- Solicitud de acreditación with the proposed scope drafted the way ONAC's annex is drafted: inspection field code, inspection activity, execution criteria, acceptance and rejection criteria, and body type
- Internal inspection procedures cited by exact name and version number, in the style of "Ultrasonido — Medición de Espesores con Scan B en Tuberías de perforación (Drill Pipe - Heavy Weight) y tubería de producción (Tubing) V.8"
- Controlled copies of every normative document named in the scope, at the edition named: DS-1 Drill Stem Inspection Vol. 3 5th ed. 2020, ASME BPVC.V-2023 Article 23 SE-797, API Spec 5CT 11th ed. December 2023, API RP 5C1 8th ed. 2020, API Std 653
- Impartiality analysis and the declared type A, B or C under ISO/IEC 17020:2012
- Personnel competence records covering certification, authorisation, training, witnessed performance and ongoing monitoring per ISO/IEC 17020 clause 6.1
- Equipment inventory with calibration and verification records for each method in the scope
- Inspection reports and certificates in the format ONAC assessed, with the accreditation symbol applied per ONAC's rules of use
- Fee calculation from ONAC's Modelo Integral de Tarifas (MIT)
- For the hydrocarbon scopes, the ANH technical guidance annexes and documented method for flare efficiency evaluation and leak quantification
Findings to close before the audit
- Scope creep: the firm inspects a tubular size or applies a normative document that is not in the annexed scope, so the report cannot legitimately carry the accreditation mark
- The internal procedure version named in the ONAC annex has been superseded internally without notifying ONAC of the change
- Acceptance criteria applied from a different edition than the annex names; DS-1 Volume 3, 5th edition 2020, clause 3.6.5 and tables 3.6.1, 3.6.2 and 3.11.2 are specific, and an older edition's tables are a finding
- A type C inspection body performing work that, as contracted, makes it supplier or repairer of the item inspected, breaking the declared impartiality arrangement
- Personnel file rests solely on an SNT-TC-1A employer card, with no evidence of the competence authorisation and ongoing monitoring ISO/IEC 17020 clause 6.1 requires
- Flare efficiency and leak reports issued without reference to the ANH technical guidance, or without demonstrating the 90 per cent combustion and methane destruction efficiency threshold set out in ANH Circular No. 0003 of 30 January 2025
- Accreditation symbol used on reports outside the accredited scope, or on general marketing material
- Surveillance dates missed because the firm counted from the certificate date rather than from the DOA publication that actually starts the cycle
Related: the ONAC overview, outsourced ASNT Level III cover, written practice development, NDT procedure development, a programme gap assessment, interim Level III cover.