The amended UK clinical trials regulations have applied since 28 April 2026. Here is what changed in approvals, modifications, transparency and GCP, and what each change asks of the systems that hold your trial data. General information, not legal advice.
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Days
7 days
14 days from validation
30 days from validation
35 days from validation
Before first consent or 90 days after approval
Key points
The reform
The reform is the largest change to UK trial law since the 2004 regulations. The MHRA announced it in March 2023 after a consultation with more than 2,000 responses, and the final instrument went through Parliament in draft before being made in April 2025 with a 12-month lead-in. The language changed too: "amendments" are now modifications, and "subjects" are now participants.
Trials applied for before 28 April 2026 are treated as old rules trials under the transitional arrangements, but most GCP and conduct changes apply to every CTIMP running in the UK from that date. Read the MHRA transitional arrangements guidance for which parts apply to an ongoing trial. If you are choosing software for a UK study, the clinical trial software for the UK page covers hosting, UK GDPR and NHS sites; this page stays on the regulations.
One application through IRAS covers the MHRA and the ethics committee. The MHRA guidance sets maximum timelines in calendar days: a validation outcome within 7 days, an initial decision within 30 days of validation (up to 120 if an expert committee is consulted), 60 days for the applicant to answer a request for further information, and a decision within 10 days of the response. A trial cannot start until both approvals are in place.
A trial can be notified rather than fully assessed if it meets one of three conditions: the medicine is used within its licence or established practice (A), it repeats dosing from a previous UK approval (B), or another regulator has approved the trial (C). Exclusion criteria apply. The MHRA confirms eligible trials within 14 days of validation, and the ethics decision follows within 30.
Modifications
From the MHRA guidance on modifying a clinical trial approval. Use the MHRA modification tool for your actual change.
| Category | What it means | Timeline | Data system examples given or implied |
|---|---|---|---|
| Route A substantial | Likely to substantially affect participant safety or rights, or the reliability of trial data; full assessment | Decision within 35 days of validation | Changing the assessments used at safety monitoring visits; changing SAE recording |
| Route B substantial | Meets regulation 11B criteria and no new safety concerns; automatic approval | Confirmation within 14 days; combined decision within 35 | Changes that fit the published Route B examples |
| Modification of an important detail | No significant impact, but the authorities need to know | Notify; no fee | Sponsor changes, new trial locations |
| Minor | Low risk; no notification, keep records | None | Changes to record-keeping processes or technical equipment |
Whether a CRF or system change is minor or substantial depends on its effect on safety and data reliability. Record the reasoning either way.
Transparency
For the first time, UK law requires CTIMP sponsors to register their trial in a public registry: before the first participant gives consent or within 90 days of approval, whichever is earlier. A summary of results must be published in the same registry within 12 months of the end of the trial, and participants must be offered a summary they can understand. Phase I trials can get an automatic deferral of up to 30 months for results, and failing to register or publish is an offence. The ClinicalTrials.gov registration guide walks through one common registry.
For the data system, a 12-month results clock means the path from last participant visit to clean, locked data has to be planned from day one. Outcomes on the registry record should match fields on your forms, and query resolution, coding and database lock need to fit inside the window with time left for analysis and writing.
Set up forms, edit checks and exports in the free sandbox and test them before your combined review. No credit card; pay only when you go live.
What changes for data systems
The regulations do not name EDC systems, but several changes land on them directly.
Regulation 28 makes compliance with the ICH E6 GCP principles a legal requirement, and sponsors must have regard to relevant guidance. MHRA guidance names maintaining trial-specific computerised systems as a sponsor function and expects them to be fit for purpose.
MHRA's quality and risk proportionality guidance asks sponsors to identify critical-to-quality factors early. Validation of systems used for clinical data or endpoints is one of them. Scale testing to what is critical.
Keep a change log for forms and configuration that shows what changed, when, who approved it and how you classified it.
MHRA archiving guidance says records should generally be kept for at least 25 years after the trial ends. Plan exports and archive formats that will still be readable, with audit trails, long after the vendor contract ends.
Plan cleaning, lock and exports so the summary can be posted on time. Exports should carry a data dictionary.
Low-intervention trials can use simplified arrangements for seeking and evidencing consent, if the protocol explains them. Make sure your consent records match the approved approach.
Where Capture fits
Capture gives sponsors and clinical trials units the technical controls that the GCP principles and MHRA inspectors look for. Forms move through a draft to approved lifecycle and approved forms are locked for live use, which gives a clear record when you modify a CRF. Every change to study data is captured in a field-level audit trail with the user, timestamp, old value, new value and reason; the trail is append-only and hash-chained. Edit checks raise queries automatically when a value breaks a rule, and source data verification can be set per field, which supports a risk-proportionate monitoring plan.
Role-based access keeps participant names with site staff and coded IDs with researchers. Study data are hosted in the EU (Frankfurt) or US (N. Virginia), and export to CSV or Excel with a data dictionary, or to CDISC SDTM datasets with Define-XML, which supports results reporting and long-term archiving. These are 21 CFR Part 11 aligned controls; your validation, procedures and training make them compliant use. We do not claim ICH E6(R3) compliance; the ICH E6(R3) guide explains the expectations, and the audit-ready clinical trial data page covers inspection preparation.
The Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025 (SI 2025/538) came into force on 28 April 2026. They were made on 28 April 2025 with a 12-month implementation period.
Partly. Trials applied for before that date are old rules trials under transitional arrangements, but most GCP and conduct changes apply to all UK CTIMPs from 28 April 2026. Check the MHRA transitional arrangements guidance.
A lower-risk trial that meets one of three conditions, such as using a medicine within its licence, and none of the exclusions. The MHRA confirms eligible trials within 14 days of validation; the ethics committee decision follows within 30 days.
Register in a public registry before the first participant consents or within 90 days of approval, whichever is earlier; publish a results summary within 12 months of the end of the trial; and offer participants a summary they can understand.
It depends on the effect. Changes to safety monitoring assessments are Route A examples, while changes to record-keeping processes or technical equipment are listed as minor. Use the MHRA modification tool and record your reasoning.
No. The MHRA inspects sponsors and their use of computerised systems; it does not certify software. Sponsors must ensure systems are fit for purpose and validated in proportion to risk.
Keep exploring
Clinical trial software in the UK
Hosting, UK GDPR and NHS sites.
ICH E6(R3) guide
The GCP principles behind the law.
EMA computerised systems guideline
EU expectations for trial systems.
Risk-based monitoring and SDV
Proportionate monitoring in practice.
ClinicalTrials.gov registration guide
Registering a trial step by step.
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