Guidance

Archiving and retention of clinical trial records

Updated 14 April 2026

Legal status of this guidance 

This guidance accompanies the Medicines for Human Use (Clinical Trials) Regulations 2004, as amended by the Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025.These amendments come into force on 28 April 2026 and any reference to “the amended Clinical Trials Regulations” in this guidance should be construed as referring to the amended version.

Part 2 of Schedule 1 to the amended Clinical Trials Regulations requires that the investigator and sponsor have regard to all relevant guidance with respect to commencing and conducting a clinical trial.

Investigators and sponsors (and any individual or organisation that the sponsor delegates trial related activities to) must, therefore, ensure that they are fully aware of the information within this guidance and act accordingly to achieve and maintain regulatory compliance. 

Essential documents definition 

The term “essential documents” in regulation 31A is defined as those documents which (a) enable both the conduct of the clinical trial and the quality of the data produced to be evaluated, and (b) show whether the trial is, or has been, conducted in accordance with the relevant requirements of the Clinical Trial Regulations. For purposes of meeting this definition, the MHRA recognises the ICH GCP E6 (R3) definition of essential records.

‘Essential records are the documents and data (and relevant metadata), in any format, associated with a clinical trial that facilitate the ongoing management of the trial and collectively allow the evaluation of the methods used, the factors affecting a trial and the actions taken during the trial conduct to determine the reliability of the trial results produced and the verification that the trial was conducted in accordance with GCP and applicable regulatory requirements…’.  

Appendix C of ICH GCP E6 (R3) gives further guidance on what records should be considered essential and therefore require retention as essential documents as per Regulation 31A of the amended Clinical Trials Regulations.

Legal and regulatory framework 

The amended Clinical Trials Regulations requires sponsors to maintain a Trial Master File (TMF) containing essential documents that enable evaluation of trial conduct and data quality. 

Regulation 31A of the amended Clinical Trials Regulations mandates retention of essential documents and participant medical files for at least 25 years from the conclusion of the trial, or longer if required for marketing authorisation purposes. 

Medical file is to be considered synonymous with health record as defined in Access to Health Records Act 1990 and the Data Protection Act 2018. For the avoidance of doubt this includes records related to healthy participants in a clinical trial.

ICH E6(R3) Good Clinical Practice requires essential records to be complete, legible, and readily available for inspection throughout the retention period. 

Retention periods 

Retention of the essential documents within the TMF (including the investigator site file) and the medical files of trial participants is a legal requirement as described in Regulation 31A of the amended Clinical Trials Regulations.

The sponsor and the investigator, and any delegated service providers, must ensure that the documents contained, or that have been contained, in the TMF, as well as the medical files of trial participants are retained for at least 25 years beginning the day after the conclusion of the trial.  

If at the date of the expiry of the 25 years, the data generated by the trial is being used to support an application for a UK marketing authorisation, the sponsor shall ensure the essential documents are retained for at least the period of 2 years beginning with the day after the grant of that UK marketing authorisation per Regulation 31A (7A) of the amended Clinical Trials Regulations.

For authorised products, the Human Medicines Regulations 2012, via Regulation 50(5) reference to Annex 1 of the 2001/83/EC Directive includes requirements for the retention of all other documentation pertaining to the trial by the sponsor or other owner of the data for as long as the product is authorised with the final clinical study report being retained for 5 years after the product is no longer authorised. 

There are also additional considerations for:

• participant medical files which may be required to be retained for longer than 25 years if required by other legislation or by institutional policy such as NHS Records Management Code of Practice 

• advanced therapy investigational medicinal products where traceability records are required to be retained for 30 years after product expiry or longer if required by the clinical trial authorisation

Sponsors, investigators and delegated service providers must ensure that essential documents are readily available, complete, and legible at all times during the retention period for inspection by the MHRA or other competent authorities. 

Named person responsible for archiving 

Regulation 31A (9) of the amended Clinical Trials Regulations requires that the sponsor appoints a named individual within the organisation to be responsible for archiving the documents which are, or have been, contained in the TMF, and that access to these documents must be restricted to those appointed individuals and auditors or inspectors.  

It should be noted that the named individual should have oversight of the retention of those records which are electronic in nature as well as paper-based records. 

Archiving and data integrity 

The MHRA GXP data integrity guidance states the MHRA’s position on requirements for archiving of essential records to ensure data integrity and the minimum expectation to achieve compliance. Examples of such include: 

• security and access: access to archived records should be restricted to named individuals appointed by the sponsor 

• format and authenticity: original records or certified true copies should be retained. Scanning processes should be validated to ensure authenticity and completeness 

• electronic records: systems should maintain audit trails, metadata, and ensure long-term readability. Migration to new formats should be validated and documented 

• environmental controls: storage conditions should protect against deterioration, fire, flood, pests, and unauthorised access

It is expected that investigators and sponsors (and any individual or organisation that the sponsor delegates trial related activities to) have due regard to the expectations contained in the MHRA GXP data integrity guidance. 

Transfer of ownership 

Where there is a change of ownership of essential documents connected with the clinical trial, for example, transfer of a marketing authorisation to another organisation, then the sponsor must record the transfer, and the new owner must be responsible for ongoing data retention and archiving. 

Where a sponsor closes (for example goes into administration) then the record retention requirements remain with the Chief Investigator per Regulation 31A (7) of the amended Clinical Trials Regulations. The TMF must remain accessible and complete to ensure compliance with regulatory requirements and to safeguard participant data. 

Destruction of documents 

Documents must not be destroyed before the end of the retention period. 

Where documents have been damaged or destroyed accidentally then an assessment should be conducted to determine the extent and impact of the lost or damaged documents. If the assessment is found to impact on the ability to present the documents for inspection then a serious breach notification should be considered. 

Implications for transitional provisions

All trials, regardless of whether the clinical trial application was submitted prior to, on or after the day on which the amendments to the Clinical Trials Regulations come into force (28 April 2026), must comply with regulation 31A of the amended Clinical Trials Regulations, except for regulation 31A (7). Where the clinical trial application was submitted prior to 28 April 2026, regulation 31A (7) of the unamended Clinical Trials Regulations (the version prior to 28 April 2026) applies (as per Schedule 14 of the amended Clinical Trials Regulations).

For the avoidance of doubt: 

• where clinical trial applications were submitted before the day on which the amendments to the Clinical Trials Regulations came into force (28 April 2026), those trials must comply with retention and archiving obligations stipulated as follows:

• the sponsor and the chief investigator shall ensure that the documents contained, or which have been contained, in the trial master file are retained for at least 5 years after the conclusion of the trial and that during that period are (a) readily available to the licensing authority on request; and (b) complete and legible 

• if, at the date of the expiry of the 5 years, the data generated by the trial is being used to support an application for a UK marketing authorisation, the sponsor shall ensure the essential records are retained for at least the period of 2 years beginning with the day after the granting of that UK marketing authorisation

• the sponsor and chief investigator shall ensure that the medical files of trial participants are retained for at least the period of 25 years beginning with the day after conclusion of the trial, or such period as is required by any other enactment, if longer

• where the clinical trial applications were submitted on or after 28 April 2026, those trials must comply with amended Clinical Trials Regulations for retention and archiving obligations as outlined above. The main difference is that, for these trials, the documents contained, or which have been contained, in the trial master file must be retained for at least 25 years after the conclusion of the trial (rather than 5 years).

• for all trials, regardless of when the trial application was submitted, that relate to an authorised product then all other documentation pertaining to the trial must be retained for as long as the product is authorised with the final clinical study report being retained for 5 years after the product is no longer authorised (Regulations 50 (5) Human Medicines Regulations 2012 (SI 2012:1916).