Conflict Minerals Due Diligence 2026 — Turning CMRT Compliance Into a System

A request lands from a customer asking you to submit a CMRT, and nobody inside the company has an answer ready. That is how a great many manufacturers first come to look seriously at conflict minerals due diligence. This article sets out the basics of the 3TG minerals covered, what changed in CMRT 6.6, why spreadsheet-based workflows eventually break down, and how to move to a system that links your bill of materials to smelter information. It also covers the difficulties specific to a plant in Thailand, together with a worked estimate of the effort involved.

What conflict minerals due diligence is – 3TG and the basics of responsible minerals sourcing

Start by agreeing on what the term actually refers to. If that stays vague, quality assurance, procurement, and engineering will each sit through the same meeting picturing something different.

The scope is four minerals, known as 3TG

The minerals originally brought into scope were tin, tantalum, tungsten, and gold. The industry shorthand is 3TG, from the initial letters of the first three plus the G of gold.

These four were singled out because revenue from mining them in certain regions has been used to fund armed groups. The disclosure obligation that grew out of the US Dodd-Frank Act is the starting point of the framework, and from there it developed into the industry-wide survey templates used today.

The important thing to grasp is that these minerals are not confined to exotic components. Tin is in solder. Tantalum is in capacitors. Tungsten turns up in cutting tools and weight components. Gold is used in plating and bonding wire. As long as a company makes electronics or automotive parts, it is very unlikely to fall outside the scope.

You are being asked and doing the asking at the same time

What makes conflict minerals work unusual in practice is that survey requests cascade down the supply chain. The OEM shipping the finished product carries the disclosure obligation, and it sends the survey to its Tier 1 suppliers. Tier 1 cannot answer alone, so it sends the same survey to Tier 2. The chain continues to the far end.

That means a manufacturer sitting in the middle is simultaneously the party being asked by customers and the party asking its own suppliers. On top of that, every customer sets a different deadline, and every supplier responds at a different speed and a different level of accuracy. In a very large number of companies, both roles land on one person, and that is the root of the workload problem discussed later.

What you track is provenance information, not physical goods

This is the biggest difference from traceability in the general sense. Traceability inside a plant follows physical items – which product or part passed through which process and when. Conflict minerals due diligence follows something else entirely, namely which smelters and refiners the minerals inside a part passed through.

The goods are on your own site. The smelter sits far outside your span of control, behind your supplier and your supplier’s supplier. You cannot go and verify it physically. You can only reach it through an accumulation of declaration documents. Teams that try to bolt this onto an existing production management system without understanding that structural difference tend to spend months without ever settling the requirements.

The latest on CMRT reporting and EMRT compliance – what changed in 2026

Next comes the paperwork you actually handle. Version control matters more here than it might appear, because answering on an outdated template is a common reason for a submission to be sent back.

How CMRT, EMRT, and AMRT divide the work

The industry-standard survey templates for responsible minerals sourcing are maintained by the Responsible Minerals Initiative, or RMI. There is a separate template per group of minerals, and three of them come up in day-to-day work.

CMRT is the centre of gravity, but companies touching EV work or battery materials are increasingly asked for EMRT compliance at the same time, because cobalt is unavoidable in the supply chain for battery cells and electrode materials. It is not only the template that differs – the smelters you end up asking about and the suppliers you collect answers from change too, so a CMRT workflow does not simply extend sideways to cover it.

The main changes in CMRT 6.6

RMI published CMRT 6.6 on 17 April 2026. The main changes in that release are as follows.

The overall shape of the compliance obligation has not changed dramatically. What has moved up the priority list is checking the new smelter list against your own supply chain, and responding quickly when a relationship with a high-risk smelter comes to light.

The addition of the Requester Product Number field deserves particular attention. Read the other way round, it signals that the expected granularity of an answer is shifting from “how does your company look overall” to “how does this specific part number look”. Companies that have historically answered at company level are the ones most affected by that shift.

Recommended template versions for the 2026 reporting year

For the 2026 reporting year, RMI recommends using CMRT 6.6, EMRT 2.11, and AMRT 1.31 or later. Even when the template a customer distributes is an older version, keeping the master data you build your answers from aligned with the current version tends to save rework later.

There is a second point worth registering about 2026 practice. A static CMRT – one produced once and then reused – is increasingly regarded as high risk. The direction of travel is away from a single annual distribution of survey forms and toward continuous due diligence, ongoing engagement with suppliers, and a defined escalation path for when smelter data changes.

In the EU, too, there is growing pressure on companies to explain which parts contain the minerals in scope and which suppliers and smelters they pass through. Simply transcribing a supplier’s self-declaration is becoming inadequate against a requirement for evidence-based risk management.

The five-step OECD framework underneath it all

So what does continuous due diligence consist of in concrete terms? The reference point here is the five steps set out in the OECD due diligence guidance. RMI, JEITA, and corporate CSR disclosures all describe their own programmes broadly along this skeleton.

What stands out from these five steps is that the hands-on work sits in steps 2 and 3, and that those are where the volume of information is overwhelmingly greatest. They are also where systemisation pays back fastest. Steps 1 and 5, by contrast, are mostly documentation – a question of internal policy and organisation rather than software.

In Japan, JEITA, the Japan Electronics and Information Technology Industries Association, addresses this theme continuously on behalf of the industry, and held a responsible minerals sourcing briefing on 25 June 2026. The simple fact that such a briefing is held every year says a good deal – this is not a passing topic but a permanent operational responsibility for Japanese electronic component makers and EMS providers.

Why manual spreadsheet-based conflict minerals due diligence breaks down

Most companies start in a spreadsheet, and there is nothing wrong with that. The problem is that as part counts and supplier counts grow, the workload does not rise linearly. It rises sharply.

Where the annual effort actually goes

Break down the work required to complete a single CMRT report and it looks like this.

The two stages that consume the most time are almost always chasing responses and resolving unknowns. Both depend on somebody else’s schedule, so no amount of internal effort shortens them. That is precisely why starting earlier and having visibility of progress make such a difference.

Why unknowns keep coming back

Among large electronic component makers, annual CMRT surveys of direct suppliers achieve response rates in the ninety percent range. Even so, a certain number of responses come back with the smelter information still recorded as unknown.

This is not bad faith on the supplier’s part. They cannot answer without asking their own suppliers, and the same structure repeats one level further down. The granularity of the information drops with every tier you descend, and the proportion of unknowns rises as you approach the far end of the chain.

Clearing those unknowns is, in substance, an escalation process with suppliers. Without a record of who was asked what and when, and how the answer changed, you will be asking the same question of the same company in the same place next year. The weakness of spreadsheets is exactly here, in the accumulation of history. Saving files with a date in the filename produces a record, but not a history you can query.

Why a static CMRT is itself a risk

As noted above, a CMRT produced once and reused is regarded as high risk as of 2026. The reason is straightforward – the smelter list is updated every year.

A smelter that raised no concerns when you answered last year can be newly flagged in this year’s list update. If you submit a copy of last year’s CMRT, you will report no issues without ever noticing the change, and that can amount to a disclosure that does not match the facts.

What you need, in other words, is not an annual burst of work but a state in which you can determine whether an update to the smelter master affects your own answers. Attempting that in spreadsheets leaves you opening every file and reconciling by hand.

Systemising 3TG traceability – the three data sets you have to link

Here is the core of it. Systemising conflict minerals due diligence comes down to holding three kinds of data linked together, in a state that can keep up with updates.

BOM, supplier declarations, and the smelter master

Three data sets sit at the centre.

As long as those three live in separate spreadsheets, you cannot trace the impact of a change in any one of them. Turn that around and the implication is encouraging – simply joining the three on shared keys inside one database transforms what you can see.

Suppose the smelter master is updated. You look up which supplier declarations name that smelter, then look up from the BOM which parts those suppliers provide, and the affected products fall out automatically. The impact assessment that previously meant opening every file and reconciling manually becomes a single query.

Ordering the functionality by priority

None of which means you have to build something complete on day one. Phasing the work by where the return appears fastest is far more realistic.

For most companies the strongest return is in phases 1 and 2. Those alone visibly reduce the load on the person doing the work. Phase 3 onwards depends heavily on the state of your BOM, so check the condition of your existing production management system or PLM before committing.

How this relates to traceability work you already have

It is worth being clear about how this sits alongside other traceability initiatives inside the company.

If you work with electronic components, you may already have internal traceability built on lots and serial numbers. On that front, the discussion of tracking granularity and cost structure in our article on building an electronic component traceability system is a useful reference. What it tracks, though, is the movement of physical goods through your own processes – mineral origin and smelters are outside its scope. Treat conflict minerals due diligence as a separate axis extending beyond it.

The same applies in automotive parts. The customer audit and corrective action practices covered in our article on automotive parts traceability and IATF 16949 compliance are extremely important as a quality assurance framework, but mineral sourcing is not what those audits are about. The two address the same industries under different regulatory themes.

Our practical recommendation is not to force this into your existing traceability platform. The data granularity, update frequency, and owning department all differ, and merging them muddies both sets of requirements. Sharing only the BOM as a common key, while keeping the two as independent systems, produces a more stable operation.

Design to reduce the burden on suppliers

This is easily overlooked, but the success of the whole arrangement rests on how willing your suppliers are to cooperate. However sophisticated your internal management becomes, nothing moves if the other side does not answer.

The following considerations do the most to lift response rates.

• Narrow the parts you ask about, rather than surveying everything including parts with no possibility of mineral content.
• Show suppliers their previous year’s response, so that they only have to confirm when nothing has changed.
• Put the recipient, the deadline, and the template version in the same position and the same format in every request.
• Standardise on the industry template rather than issuing a different response format for each customer.

The single most effective of these is showing last year’s answer and asking only for the differences. Making suppliers fill in a blank form from scratch every year is the approach they resent most, and the response quality suffers accordingly.

The difficulty of running conflict minerals due diligence from a plant in Thailand

Everything so far applies generally. Companies with manufacturing in Thailand face some circumstances of their own.

A supply chain that is both deeply tiered and increasingly multinational

Thailand is a major production base for automotive parts and for EMS, meaning contract electronics manufacturing. Tier 1 and Tier 2 suppliers to both Japanese and Western OEMs are concentrated here, and that depth has been a source of the country’s competitiveness.

At the same time, rising EV-related investment has brought a wave of Chinese suppliers into Thailand. Reporting indicates 183 new entrants between 2023 and June 2025, pushing the supply chain further toward multinational sourcing across more tiers.

A wider choice of suppliers is welcome in itself, but from a conflict minerals perspective it raises the difficulty, for the following reasons.

• More suppliers with a short trading history, so there is no previous response to refer back to.
• Communication spread across Japanese, English, Thai, and Chinese, making the intent of a request harder to convey precisely.
• No settled owning department on the supplier side, so identifying the right contact takes time.
• Smelter information at the far end reachable only through overseas suppliers outside your span of control.

When head office in Japan asks the Thai site to run this to the same standard, failing to account for those conditions simply exhausts the local team. In practice, it is important to agree response-rate targets and start dates with head office in light of local conditions.

A worked estimate of the effort involved

To give a sense of scale, here is an estimate based on a model EMS plant in Thailand. These are our own calculations, and the actual figures vary from company to company.

For a plant of that size continuing with manual spreadsheet work, our estimate of the annual effort – sending requests, chasing, checking what comes back, resolving unknowns, and consolidating – comes to roughly 25 person-days for one person. That is more than a month of actual working time absorbed by this task alone.

With a system in place, linking the BOM to the smelter master, automating chasing, and retaining response history, that annual effort could plausibly be compressed to around 10 person-days. How much weight to put on the 15-day difference depends on the company, but the more interesting point is not the size of the reduction. It is which work disappears.

What systemisation eliminates, in short, is time spent transcribing and searching – work that requires no judgement. What remains is deciding how to respond when a risk surfaces, and that is the job the person was hired to do. Framing the objective as redirecting their time toward judgement, rather than as cutting hours, also makes the internal case easier to argue.

How to embed responsible minerals sourcing as a routine

Finally, here is a sensible order in which to start.

What to do in the first 90 days

Trying to do everything at once guarantees a stall. Restrict the first three months to three things.

• Document the criteria for identifying parts in scope. Record which materials and which part categories you treat as candidates for mineral content, and why. If this stays vague, a different person will extract a different set next year.
• Consolidate the supplier register into one. Procurement’s vendor master, quality’s approved supplier list, and an individual’s personal tracking sheet exist separately in a great many companies, and until they are merged you cannot begin sending requests.
• Collect last year’s responses in one place and produce a list of which smelters were declared. Without that list you cannot assess the impact when the smelter master is updated.

Settle internal responsibilities first

Conflict minerals due diligence crosses departmental boundaries. Unless you decide who owns what at the outset, nobody moves when a request stalls.

The third row is the one that matters most. Which parts might contain the minerals in scope can ultimately only be judged from design information. Run the process out of procurement alone and the identification of parts becomes guesswork, leaving gaps.

Keeping the customer’s trust

In practice, what customers actually look at is not whether the answer is perfect. It is these three things.

• Did you submit on time?
• Where information is unknown, do you say so honestly and explain what you are doing to resolve it?
• Can you explain what has changed since last year?

Residual unknowns are unavoidable in a deeply tiered supply chain. What causes problems is concealing them, and having nothing change from one year to the next. The shift toward continuous due diligence is, at bottom, a demand for exactly that – a state in which you can explain the change.

Frequently asked questions

What is CMRT?

CMRT is the conflict minerals survey template maintained by the Responsible Minerals Initiative (RMI). It serves as a common format for declaring whether the 3TG minerals – tin, tantalum, tungsten, and gold – are present in your products, and which smelters and refiners they passed through.

It grew out of the disclosure obligation originating in the US Dodd-Frank Act and is now an industry standard, particularly in electronics and automotive, distributed from customers down through their suppliers in a cascade. The sister template covering cobalt and mica is EMRT, which companies working with EV and battery materials are also asked to submit. The current release is CMRT 6.6, published on 17 April 2026, and RMI recommends CMRT 6.6, EMRT 2.11, and AMRT 1.31 or later for the 2026 reporting year.

By when do we need to comply?

There is no single statutory deadline. In practice the deadline set by the customer requesting submission is what governs. Most companies run an annual cycle, and the timing of requests generally differs from one major customer to the next.

In terms of preparation, waiting for the request to arrive is already too late. Collection from suppliers takes time, and resolving unknown responses requires the supplier to enquire further down their own chain. Working backwards, starting your supplier survey several months before you expect the customer request is the realistic approach. In a year when the template has been revised, as with CMRT 6.6, checking the versions of your internal master data and past responses first will save rework.

What happens if we do not comply?

For most Japanese-affiliated manufacturers the most immediate consequence is commercial. CMRT submission is frequently written into the terms of business with a customer, so failing to submit, or submitting something inadequate, surfaces as exclusion from new enquiries or as a finding in an audit.

Beyond that, as of 2026 the practice of reusing a previously produced response is itself increasingly treated as a risk. Because the smelter list is updated annually, submitting a copy of last year’s answer means you may report no issues while overlooking a newly identified high-risk smelter. A disclosure that does not match the facts is a more serious problem than simply being behind schedule. Having a mechanism that can be updated continuously is itself a risk mitigation.

Summary

Here are the key points when taking on conflict minerals due diligence.

• The scope is 3TG – tin, tantalum, tungsten, and gold. They appear in solder, capacitors, cutting tools, plating, and much else, so almost no electronics or automotive manufacturer is unaffected.
• Surveys cascade from OEMs to the far end of the chain, so a manufacturer in the middle has to act as both the party asked and the party asking.
• CMRT covers 3TG and EMRT covers cobalt and mica. RMI recommends CMRT 6.6, EMRT 2.11, and AMRT 1.31 or later for the 2026 reporting year.
• CMRT 6.6 added the Requester Product Number field, updated ISO codes, improved IPC-1755 compatibility, and refreshed the smelter list. The direction is toward answering at part-number level.
• In 2026 a static CMRT is regarded as high risk. Continuous due diligence and a working escalation path are becoming the baseline expectation.
• The operational skeleton is the five-step OECD guidance. The hands-on work sits in risk identification and assessment and in response strategy, and that is where systemisation pays back.
• Systemisation means linking three data sets – the BOM, supplier declarations, and the smelter master. If you phase the work, start with centralised collection status and automatic checking against the smelter master.
• A Thai site faces added difficulty from deeper tiers and more nationalities in the chain. In our model estimate, an annual effort of 25 person-days could plausibly be compressed to around 10.

Where you should start depends on your part count, your supplier count, and the state of your existing BOM. It is entirely fine to get in touch before any internal direction has been settled. TOMAS TECH is based in Bangkok, building production management systems and traceability platforms for Japanese-affiliated manufacturers, and we are happy to help simply with organising your current workflow or giving a view on feasibility. Please reach out through our contact form.

References

• How Conflict Mineral Reporting Template 6.6 Impacts Your Compliance Obligations – Z2Data
• How to Complete the CMRT Template – 2026 Step-by-Step Guide – Regilient
• JEITA (Japan Electronics and Information Technology Industries Association) – Responsible Minerals Sourcing programme overview
• JEITA – Responsible Minerals Sourcing Briefing 2026 background material, 25 June 2026
• Expansion scenarios for Chinese-affiliated suppliers into Thailand and ASEAN – THAIBIZ