CE Marking Checklist for Radio Modules: A 10-Point Guide for the EU & UK

Pre-approved radio modules remain the fastest route to a CE-marked wireless product, but the approval belongs to the module, not to your product. Integrate a module into your own product and you become the manufacturer of the finished radio equipment, responsible for every essential requirement of the Radio Equipment Directive.

Placing the same product on the US or Canadian market? Read our North American checklist for pre-approved radio modules, a separate guide written for that region. 

In this article, Global Technical Director Steve Hayes outlines a 10-point CE Marking checklist for manufacturers using radio modules, and the main requirements to complete before you sign your Declaration of Conformity (DoC). 

CE marking allows a product to move freely across the 27 EU Member States by attesting that all applicable design and manufacturing requirements are met. For radio equipment, that means the Radio Equipment Directive 2014/53/EU, usually alongside other legislation such as the RoHS Directive. There is no certification process; the authorization route is a Declaration of Conformity that you draw up and sign, and by signing it you assume responsibility for the whole product.  

 

Important note: Three things have changed since this checklist was first published. 

1. The RED cybersecurity requirements under Delegated Regulation 2022/30 became applicable on 1 August 2025, bringing Articles 3(3)(d), (e) and (f) into scope for most connected radio equipment.
2. The EN 18031 series was cited in the Official Journal with restrictions, which affects whether a Notified Body route is required.   
3. And under the Product Safety and Metrology etc. (Amendment) Regulations 2024, CE marking continues to be accepted in Great Britain for the RED, so most radio equipment no longer needs a separate UKCA Mark.
   
   

1. Is the device a radio module? 

Confusion often arises between a radio module and a chipset, and that distinction determines everything that follows. A module is a self-contained transmitter subsystem with its own shielding, power supply regulation and antenna, tested and approved in a standalone configuration. A chipset is a component with no regulatory status of its own, whose RF performance is defined by the board you place it on.  

If you are working with a chipset, or with a module that has been supplied without an antenna and without a defined RF chain, none of the shortcuts below applies. You are carrying out a full conformity assessment on a new radio product.  

  

2. Does the radio module have a CE Mark, and for which requirements? 

A CE mark on a module is not a single, uniform claim. Establish which essential requirements it was assessed against.  A module may have been evaluated for Article 3.1(a) safety, 3.1(b) EMC, and 3.2 efficient use of spectrum, yet have nothing covering the 3(3) requirements. Be careful with markings that resemble the CE mark but cover something different, and be wary of modules whose only documentation is a supplier declaration with no supporting evidence. 

 

3. Do you have a copy of the Declaration of Conformity (DoC)? 

Module manufacturers must sign a DoC before placing a CE-marked device on the market. It should come with the product or be available on request. If it is not readily forthcoming, treat that as a finding rather than an inconvenience. Check that the legal manufacturer named on the DoC matches the entity you are buying from, that the module part number and hardware revision on the DoC match what has actually arrived, and that a named individual has signed it. A DoC that lists a different hardware revision to the part in your build is not evidence about your part. 

  

4. Are the standards listed, current, and free of restrictions? 

The DoC should list the standards used to assess the module. Two checks are needed.   

1. First, confirm the standards are appropriate for the technology and frequency bands involved.   
2. Second, confirm they are cited in the Official Journal of the European Union (only cited standards give a presumption of conformity), and check the version.   

Standards move: a module assessed against a superseded version of a harmonized standard does not give you presumption of conformity for units you place on the market today, and there is no grandfathering under CE marking.  

Restrictions matter equally. Several standards are cited in the Official Journal with restrictions, meaning that presumption of conformity  does not apply in all circumstances. Where a restriction applies to a requirement relevant to your product, applying the standard is not sufficient on its own and a Notified Body EU-type examination certificate may be needed. Note that the certificate should be against your product; it is not allowable to carry forward a type examination certificate for the module. For more, read our whitepaper on harmonized standards with restrictions. 

  

5. Do you have a copy of the test report(s)?

A module manufacturer is not obliged to hand over test reports, but a refusal raises a reasonable question about whether the testing was done, and done properly. Without them you are signing your DoC with no evidence behind your presumption of conformity, and you have no baseline against which to compare in-host measurements later.  

When you do get them, read past the pass or fail. The useful content is the configuration: which antenna was fitted, what the measured output power and radiated spurious emissions actually were rather than just that they were inside the limit, what modes were exercised, and what margin existed. A module passing a spurious emissions limit with 1 dB of margin behaves very differently in your host from one passing with 10 dB.  

 

6. Have you modified the module or its configuration? 

Any change to the module or the way it is used can break the chain of evidence. Check the configuration in the test report and compare it to what you’re soldering down onto your PCB.  

The most common changes are a different antenna, a different frequency allocation or channel plan, a change in power supply arrangement, and firmware that alters transmit power or duty cycle. Software matters as much as hardware here: if your host firmware can change the module's transmit power, channel selection or regional settings, the module is no longer necessarily operating in the configuration that was assessed. 

  

7. Is the antenna host-mounted? 

Some modules ship with a connector instead of an integrated antenna, which is particularly common in cellular designs. In that case, the RF chain extends onto your board, usually as a PCB trace between the module and a host-mounted antenna connector. That trace, its impedance, its length, and the connector itself are all now part of the transmitter, and they are not covered by the module's approval. Verification testing of the assembled configuration is normally required, and the antenna's gain becomes an input to both your spurious emissions margin and your RF exposure assessment.  

  

8. Are you operating within the approved temperature and supply range? 

Test reports state the conditions under which compliance was demonstrated, including a temperature range and usually a supply voltage range. Outside those conditions, the evidence simply does not extend.  

Two pitfalls we see most commonly:   

1. The first is that your product's stated operating range, as printed in your own datasheet or user manual, effectively becomes a claim you must be able to support, so a wider claim than the module's tested range creates an obligation.   
2. The second is that a module inside a sealed enclosure alongside a processor and a power supply runs considerably hotter than a module on an open bench, so the ambient specification and actual junction conditions are not the same.  

If either of these are relevant to your product, these are topics that you must address, most likely through additional testing.  

 

9. Are multiple radios present and capable of simultaneous transmission? 

Where a product contains more than one transmitter that can operate at the same time, signals can combine to produce intermodulation products at frequencies neither radio generates on its own. ETSI EG 203 367 sets out how to investigate this. If any emission produced during simultaneous transmission exceeds the least stringent limit applying to the radios in isolation, the product is non-compliant.  

Two further considerations follow.   

1. If the radios physically cannot transmit at the same time, and you can demonstrate that in firmware, the investigation is not required, you still need to document and protect that constraint in your release process.   
2. And where transmitters share an antenna, which is common in combined 2.4 GHz modules carrying Wi-Fi and Bluetooth, intermodulation is considerably more likely and should be assumed to need assessment.  

 

10. Is the equipment portable, body-worn, or used against the head? 

Any product incorporating a transmitter needs an RF exposure assessment. Lower-power equipment used away from the body can often be handled by calculation against the relevant reference levels. Higher-power equipment, or equipment used close to the body, may need Specific Absorption Rate (SAR) measurement, and SAR must be performed on the end device in its final enclosure, which is why a module's SAR data cannot simply be inherited. In the EU the localized limit for the head and trunk is 2.0 W kg-1 averaged over 10 g of tissue, and separation distance assumptions in the assessment must reflect how the product is genuinely used rather than how you would prefer it to be used.  

 

The Bonus Eleventh Check: Who Owns Cybersecurity Conformity?  

This item was not on our original checklist because it was not yet in force. Since 1 August 2025, the RED cybersecurity requirements apply to radio equipment that can connect to the internet or processes certain categories of personal or financial data. Conformity is assessed at product level against the EN 18031 series, and it concerns your firmware, your update mechanism, your credential handling and your network interfaces.  

Many radio modules’ DoCs do not address this requirement. Because parts of the EN 18031 series are cited with restrictions, and because Article 17 of the RED requires either wholly applying harmonized standards or holding an EU-type examination certificate for the 3(3) requirements, this is the check most likely to send a project to a Notified Body. It is also the one most often discovered late. For more, read whitepaper on the RED cybersecurity requirements.

 

Host-Level Testing  

Although all of the points in this checklist can help with determining whether the module is suitable for use in the host product, nothing removes the requirement for testing of the final product. As above, the end product manufacturer must issue a declaration that their product is compliant – not that the module they purchased was compliant before they added it to their end product.  

Because of their very nature, the RF energy transmitted and received by radios, whether modules or otherwise, is inherently affected by the surrounding environment – conductive traces on PCBs, metallic structures within the host product, or even the slight dielectric effects of enclosure materials, can and do have an effect on the radiated emissions coming from the transmitter.  

As an easy example to imagine – if you take your home Wi-Fi router and place it inside a large metal wok, you’ve just created what many people refer to as a “Wi-Fi Gun”, a very high-gain radiator which would almost certainly fail any regulatory test. While the effects from components inside most host devices are probably considerably less extreme than this example, they cannot be ignored.  

It is typical that host integrators perform tests of output power and spurious emissions on their host products to ensure that these effects of the host do not create emissions which are non-compliant. A side-by-side comparison of the results from the module’s existing test report and the results from these host-level tests can be used as evidence to show that the emissions have not been impacted – this comparison can be kept as evidence in the event that a market surveillance authority requests it. For more, read our radio module integration whitepaper.  

 

Frequently Asked Questions  

Does a CE-marked radio module make my product CE compliant?  

No. The CE mark on a module confirms that the standalone module s has been declared fit for sale in the EU. Your product is a different piece of radio equipment, and because your name is on it, you are legally the manufacturer and must draw up and sign your own Declaration of Conformity covering every applicable essential requirement. Much of the module's conducted radio evidence will remain useful, but you will still need host-level EMC, a safety assessment, an RF exposure assessment, verification of radiated performance in the host, and cybersecurity conformity, which the module will not provide.  

 

Do I need a UKCA mark as well as a CE mark for a radio product?  

In most cases, no. Under the Product Safety and Metrology etc. (Amendment) Regulations 2024, CE marking continues to be accepted in Great Britain for legislation including the Radio Equipment Regulations 2017. There are exceptions worth checking: UK spectrum allocations differ from the EU in some bands, and where a product must satisfy both sets of requirements, it needs both a UKCA Declaration of Conformity and a CE Declaration of Conformity. Note also that the post-Brexit additions to the RED, including Articles 3(3)(d), (e) and (f), were not transposed into UK law.  

What if the module manufacturer will not give me the test reports?  

They are not obliged to, but the refusal itself is information. Without test reports, you have no evidence supporting your presumption of conformity and no baseline for comparing in-host measurements. Practical options are to make report availability a condition of purchase during supplier selection, to request a redacted version covering configuration and measured results, or to commission your own baseline measurements on the module. If none of those is possible, the safest position is to treat the module as untested, and scope your own testing accordingly.  

 

How do I know whether a harmonized standard is still valid for CE marking?  

Check the Official Journal of the European Union listing for the Radio Equipment Directive, which records the standards giving presumption of conformity, their versions, the dates from which they apply, and any restrictions. A standard being published, or describing itself as harmonized in its own scope, is not sufficient. Because each individual unit must comply with the requirements applicable when it is placed on the market, and there is no grandfathering under CE marking, the OJ listing needs re-checking periodically rather than once at project start.  

 

Does the RED cybersecurity requirement apply to my radio module or to my product?  

To your product. The requirements under Delegated Regulation 2022/30, applicable since 1 August 2025, are assessed at product level against the EN 18031 series and concern your firmware, update mechanism, credential handling and network interfaces. A module supplier cannot discharge them on your behalf, because the security behaviours being assessed are properties of the finished device. Since parts of EN 18031 are cited with restrictions, and Article 17 requires either full application of harmonized standards or an EU-type examination certificate for the 3(3) requirements, many products will need a Notified Body for this element.

 

How to apply the 10-point CE Marking checklist to your device’s compliance programme?   

Worked through in order, these checks produce most of the content of a RED compliance risk assessment: what you relied on, what evidence supports it, what you changed, and what you decided to test. That risk assessment is one of the first documents a market surveillance authority will ask for, and it is the difference between a defensible file and a signature on a DoC with nothing behind it.  

As an ISO/IEC 17065 accredited Notified Body to the RED with ISO/IEC 17025 accredited radio and EMC laboratories, Element can help you interpret which requirements apply, judge whether a module's existing evidence is valid for your host, and carry out the verification testing needed to close the gaps.   

Learn more about our accreditations and testing capability on our About Us page. 

Selling into North America as well? Our North American checklist for pre-approved radio modules covers the FCC and ISED route for the US and Canada. 

References: 

1. Radio Equipment Directive 2014/53/EU.
2. Commission Delegated Regulation (EU) 2022/30 – RED cybersecurity, Articles 3(3)(d), (e), (f).
3. EN 18031 series (cited in the Official Journal of the EU with restrictions).
4. ETSI EG 203 367 – guide to assessing co-located transmitters.
5. Product Safety and Metrology etc. (Amendment) Regulations 2024.
6. Radio Equipment Regulations 2017 (UK).
7. ISO/IEC 17065 (certification bodies); ISO/IEC 17025 (test laboratories).
8. Official Journal of the European Union – RED harmonised standards listing.