NABL is the National Accreditation Board for Testing and Calibration Laboratories. In India, "NABL accreditation" usually means a laboratory has been assessed against ISO/IEC 17025 and found technically competent for a defined scope of tests or calibrations. The assessment looks at both the lab's technical work and its management system, and it repeats through a surveillance cycle.
Last reviewed: 17 October 2026. Facts checked. We opened nabl-india.org and read its notices and document list. We also searched for general descriptions of the process. We did not open the NABL documents themselves (such as NABL 100B or NABL 219), and we did not check fees. The preparation checklist below is our practical suggestion, not a list published by NABL.
What NABL accredits
According to its site, NABL accredits testing and calibration laboratories under ISO/IEC 17025. It also accredits medical laboratories (ISO 15189), proficiency testing providers (ISO/IEC 17043), reference material producers (ISO 17034) and biobanks (ISO 20387). Hospital accreditation is separate and comes from NABH.
Accreditation is granted for a scope. A lab is accredited for the specific tests, methods and ranges it was assessed on, not for "everything it does". Do not describe an entire lab as accredited if only part of it is.
The cycle, as NABL's site describes it
| Item | What the site says |
|---|---|
| Process document | NABL 100B covers the accreditation process and procedure |
| Assessment checklists | NABL 219 provides assessment forms and checklists based on ISO/IEC 17025:2017 |
| Surveillance | NABL 218A is the checklist for annual surveillance |
| Terms | NABL 131 sets terms and conditions for obtaining and maintaining accreditation |
| Validity | A notice dated 16 October 2024 says validity increased from 2 years to 4 years, with yearly onsite surveillance and reassessment every 2 years |
Older web pages still say two years. The NABL notice is the one to rely on, and you should confirm the current rule on the site before you plan.
General descriptions of the process agree on its shape: application, document review, on-site assessment, assessment of corrective actions, and a decision. Accreditation decisions can be appealed to NABL. Accreditations can also be suspended or withdrawn, and NABL publishes lists of these.
What an assessment covers
The assessment reviews technical competence and the management system. In practice that means the assessor will want to see how the lab runs, not just a quality manual. Typical areas, drawn from the structure of ISO/IEC 17025 and common practice, are:
- People: who is authorised to do each test, how competence is shown and reviewed.
- Equipment: calibration status, maintenance and how measurements are traced to a reference.
- Methods: whether the method is valid for your use, and whether you apply it as written.
- Samples: how items are received, identified, stored and handled.
- Results: how you check quality, how uncertainty is considered and how reports are reviewed.
- Environment: conditions that can affect results, such as temperature or contamination.
- Management system: document control, complaints, nonconformities, internal audits and management review.
- Impartiality and confidentiality: how the lab protects both.
A technical assessor will often witness a test being done. Be ready to run it live, with the person who normally does it.
A readiness checklist
| Check | Evidence the assessor may ask for |
|---|---|
| Scope is clear | A list of tests, methods and ranges you intend to be accredited for |
| Competence | Authorisation records, training records, observed performance |
| Equipment | Calibration certificates, due dates, intermediate checks |
| Method control | Current method copies, validation or verification records |
| Quality of results | Control charts, repeat tests, proficiency testing or comparison results |
| Reporting | Sample reports, review sign-off, amendment records |
| Internal audit | A completed audit with closed actions |
| Management review | Minutes showing decisions and follow-up |
The most useful step before the visit is an internal audit against the standard. Our guide to running an ISO internal audit shows the method, and gap assessment before ISO certification applies the same idea earlier. If you find nonconformities, our note on major and minor nonconformities explains how to write and close them. The audit checklist generator can help structure your questions.
Mistakes that cost time
- Claiming a scope the lab cannot demonstrate.
- Calibration certificates that are current but not reviewed for suitability.
- Methods in use that differ from the controlled copy.
- An internal audit done once, shortly before the visit, with no follow-up.
- Records that are complete for the last month but thin before that.
Frequently Asked Questions
What does NABL stand for?
National Accreditation Board for Testing and Calibration Laboratories.
Which standard does NABL use for testing and calibration labs?
ISO/IEC 17025. NABL's site refers to checklists based on the 2017 edition.
How long does NABL accreditation last?
NABL's notice of 16 October 2024 says validity went from 2 to 4 years, with yearly onsite surveillance and reassessment every 2 years. Confirm on nabl-india.org before relying on it.
Is NABL the same as ISO certification?
No. ISO certification usually audits a management system. NABL accreditation also assesses whether the lab is technically competent for specific tests.
Is NABL accreditation the same as NABH?
No. NABH accredits healthcare providers such as hospitals. NABL accredits laboratories.
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