The new MCS:2025 scheme changes how assessment frequency is decided. Low-risk installers can move towards reduced site assessment frequency, but that does not mean records matter less.
It means the opposite. If your certification body is using a risk model, the easiest way to avoid unnecessary friction is to make every file obvious: what was sold, what was surveyed, what was designed, what was installed, what was handed over and what was corrected.
The renewal file check
Start with a small sample of recent jobs for every certified technology. Do not only choose your neatest jobs. Include one straightforward file, one awkward file, and one file with a complaint, defect, variation or late document.
- Can you find the customer agreement and scope quickly?
- Can you identify the certified technology route used for the job?
- Can you show the survey, design, install, commissioning and handover evidence in one place?
- Can you explain any assumptions made before quote or design?
- Can someone who did not work on the job understand the file without asking the installer?
Technical Supervisor records
MCS:2025 puts clear weight on competence. The Technical Supervisor evidence should be boring, current and easy to prove.
- Name, role and technology scope for each Technical Supervisor.
- Qualification evidence and expiry dates where applicable.
- Process for checking expiry, absence, role changes or replacement supervisors.
- Evidence that the Technical Supervisor is involved in the work they are responsible for.
- Records showing how technical decisions are checked and signed off.
Installation job file
The MCS Installer Operating Requirements expect installation documentation to be kept together in a secure record system and retained for at least six years.
A good job file should make these items easy to find:
- Customer details, address and agreed scope.
- Pre-sale information and quotation evidence.
- Survey report, photographs and site notes.
- Design evidence, product selection and calculation records.
- Commissioning records and installer sign-off.
- MCS certificate or registration evidence where applicable.
- Handover pack and customer communication.
- Financial protection product evidence where required.
Survey evidence
Survey evidence is often where a weak job file starts. If the site facts are incomplete, every later decision is harder to defend.
For heat pump jobs, check that the file includes room measurements, emitter context, fabric notes, external unit siting, access, electrical evidence, plant details, cylinder notes, and MCS 020(a) context where in scope.
For solar jobs, check roof evidence, access, orientation, shading, electrical route, inverter context, consumer unit photographs, battery-ready notes and constraints.
- Heat pump survey company for installer-ready site records before quote or design.
- ASHP survey and MCS 020(a) evidence for air source heat pump jobs.
- Heat loss survey company for room-by-room inputs and calculation support.
- Solar panel survey company for PV survey evidence before design.
- Sample report for the report structure Vertex issues.
Customer records and handover
Under a risk-based approach, the customer file matters because complaints, unclear commitments and weak handover records can all create avoidable risk.
- Keep pre-sale information with the quote.
- Record changes to scope and who approved them.
- Keep handover documents in the same file as the install evidence.
- Make financial protection evidence easy to locate.
- Keep customer questions, defects and follow-up actions traceable.
Complaints, corrective action and prevention
Repeated non-conformities matter under the MCS Quality Risk Model. A complaint log that only says "resolved" is not enough if it does not show the cause and the prevention step.
- Record the complaint or issue date.
- Describe the root cause in plain language.
- Record corrective action taken on that job.
- Record preventive action to stop the same issue recurring.
- Check whether the same issue appears across more than one job.
Red flags before renewal
If any of these are true, fix them before your certification body asks:
- Job photos are stored separately with no labels.
- Heat loss assumptions are unclear or not tied to site evidence.
- Survey reports do not show constraints or inaccessible areas.
- Technical Supervisor evidence is current but hard to locate.
- Complaints have no root-cause or prevention record.
- Customer handover records are split across email, portal and paper folders.
- Different technologies use different filing habits with no clear reason.
Related reading
- MCS:2025 audit cycle guide for the full reduced, standard and enhanced assessment explanation.
- MCS certificate guide for sign-off and certification wording.
- MCS documentation guide for evidence and standards routes.
- MCS compliance survey documentation for keeping survey proof usable.