[Home](/)/[Resources](/resources)/CE Marking Size and Placement CE / EUProduct Marking # CE Marking Size and Placement Requirements: The Blue Guide Rules The CE marking is one of the most recognisable conformity symbols in global trade — and also one of the most incorrectly applied. A mark that is too small, uses the wrong proportions, appears in the wrong location, or omits the required Notified Body number is a nonconformity that can halt product clearance at the border or trigger a market surveillance action. This guide sets out the exact rules from the EU Blue Guide 2022 and the applicable product directives: minimum height, proportions, the hierarchy of placement locations, when the NB number is mandatory, permanence requirements, and the most common errors found in practice. Copy Link[Share on WhatsApp](https://wa.me/?text=https%3A%2F%2Fkrono-labs.com%2Fguides%2Fce-marking-size-placement) At a glance Minimum CE mark height 5mm Proportions Must follow Blue Guide exactly NB number Required when NB involved Permanence Visible and indelible for product lifetime ## Core rules governing CE marking dimensions and placement ### The 5mm minimum height requirement The CE marking must have a minimum height of 5mm — this is the requirement set out in the EU Blue Guide 2022 (section 4.4) and repeated in virtually every product directive that mandates CE marking. The 5mm applies to the height of the letters 'C' and 'E' in the marking. The proportions of the letters must be maintained — the CE mark cannot be stretched, compressed, or distorted. The exact proportions are specified in the Blue Guide and in the annex of each applicable directive: the vertical midstroke of each letter falls at the midpoint of the overall letter height, the opening of the C subtends 120° at the centre, and the gap between C and E equals approximately one-tenth of the overall mark height. Sourcing the official vectorised mark from the European Commission's guidance materials is the safest way to guarantee correct proportions. ### When the 5mm can be waived for small devices The Blue Guide explicitly allows the minimum 5mm dimension to be waived for small devices or components where physical size makes it technically impossible to affix a legible 5mm CE mark. Several product directives contain this provision — including the Radio Equipment Directive 2014/53/EU, the Medical Devices Regulation, and the Low Voltage Directive 2014/35/EU. Crucially, when the CE mark is not visible or legible on the device itself due to size constraints, it must be legible on the packaging and in accompanying documentation (instructions for use). The size exemption is not a licence to omit the mark — it is a licence to reduce the mark below 5mm when genuinely necessary, while maintaining it on all accompanying materials. Document the technical justification for any sub-5mm application in the technical file. ### CE marking on the product vs on the packaging The CE marking must be affixed to the product. If affixing to the product is not possible due to its nature or size, the mark is placed on the packaging. A third option — affixing it to documents accompanying the product — is reserved for product categories where the applicable directive specifically allows it. The hierarchy matters for market surveillance: inspectors look for the CE mark on the product first. For products sold in retail packaging, the product and the outer retail packaging must carry the CE mark alongside other mandatory markings (importer details, manufacturer address, WEEE symbol where applicable). Affixing CE marking only to the instruction manual or only to the shipping carton does not satisfy the requirement where the product can physically carry the mark. ### The Notified Body number — when it must accompany CE marking When a Notified Body has been involved in the conformity assessment process — meaning the product required third-party certification rather than self-declaration under Module A — the four-digit NB number must be affixed immediately after the CE marking. The format is: 'CE' followed by the four-digit number with no space between CE and the number (e.g., CE0197 for BSI, CE0120 for TÜV Rheinland, CE0044 for TÜV SÜD). The NB number is not required for products where the manufacturer self-declares conformity — for example, Class I medical devices, or electrical products assessed under Module A of the Low Voltage Directive. For products where multiple NB numbers could apply, the number of the NB responsible for ongoing production surveillance is used. The NB number must remain with the CE mark wherever the mark appears — on the product, on the packaging, and in the DoC. ### Permanence and visibility requirements The CE marking must be visible, legible, and indelible. It must remain clearly legible throughout the reasonably foreseeable lifetime of the product under normal and foreseeable conditions of use. An adhesive label is acceptable provided it meets the permanence requirement — a label that can be easily removed without evidence of tampering, or that will peel off under normal use or environmental exposure, does not meet the indelibility requirement. Compliant permanent methods include: laser etching for plastic and metal housings, engraving for metal panels, direct UV or screen printing for plastic components, and high-durability pressure-sensitive labels with adequate adhesive for the substrate and expected environmental conditions (temperature, humidity, chemical exposure). The marking must be visible without requiring the user to dismantle the product — placement inside a compartment accessible only by removing panels is non-compliant. ### Common CE marking mistakes that trigger market surveillance action The most frequent errors identified in market surveillance exercises across EU member states: (1) CE marking too small — marks below 3mm are routinely found on electronic modules, PCBs, and compact consumer electronics; (2) Distorted proportions — marks stretched horizontally or vertically, typically caused by using a generic font-based 'CE' rather than the official graphical form; (3) Missing NB number on products that required NB involvement — a gap that creates immediate nonconformity; (4) CE mark placed only on outer shipping packaging, not on the retail product or retail packaging; (5) Incorrect typeface — the CE marking must follow the exact graphical form in the Blue Guide, not an arbitrary 'CE' in any convenient font; (6) CE-like marks used on non-CE-compliant products — Regulation (EC) No 765/2008 treats this as misleading use of a conformity marking and market surveillance authorities treat it seriously. ## How to correctly apply the CE marking on your product 01 Determine which EU directives and regulations require CE marking for your product. List all applicable legislation — for example, LVD 2014/35/EU, EMC Directive 2014/30/EU, RED 2014/53/EU, RoHS 2011/65/EU, Machinery Directive 2006/42/EC. Each applicable directive that requires CE marking mandates the same physical CE mark — one CE mark covers all applicable directives simultaneously. There is no separate mark per directive, and you do not need to indicate which directives apply on the CE mark itself (that information goes in the Declaration of Conformity). 02 Identify whether a Notified Body was involved in the conformity assessment for any of the applicable directives. Review the conformity assessment module selected for each directive. If any directive required NB involvement — Module B (EC type examination), Module D (production quality assurance with NB oversight), Module F (product verification by NB), or Module H (full QA system certified by NB) — obtain the NB's four-digit EU designation number from the NANDO database. This number must be affixed immediately after the CE mark on the product, packaging, and in the DoC. 03 Measure the product surface area available for mandatory markings. Identify the specific location on the product where the CE mark will be affixed — it should be visible without requiring disassembly or the opening of panels not intended for end-user access. For very small products (PCB modules, compact components, miniature connectors), assess whether the 5mm height requirement can physically be met on the product surface. If it cannot, document the technical justification and plan for compliant placement on the packaging and in the documentation. 04 Source the CE marking artwork to the correct proportions specified in the Blue Guide. Do not create a mark by typing 'CE' in any available font. Source the official vectorised CE mark from the European Commission's Blue Guide publication or from the annex of the applicable product directive — these provide the exact graphical form with correct letter proportions and spacing. Size the artwork so that the letter height is at minimum 5mm, or as large as the available space reasonably allows for small products. 05 Determine the exact placement location on the product. The CE mark should be placed near other mandatory markings — manufacturer name, registered address, model or type number, batch or serial code, rated voltage and power where applicable. For products with a rating plate or type label, grouping the CE mark on or adjacent to this label is common practice and presents well to market surveillance inspectors. Avoid placing the mark in a position where it could be confused with decorative graphics or obscured by cables and connectors in normal use. 06 Affix the CE marking using a permanent method matched to the substrate. Laser etching is the preferred method for plastic and metal housings in consumer electronics. Engraving is used for metal panels and nameplates. Screen printing and direct UV printing are used for plastic housings where the method can achieve the required durability. High-durability pressure-sensitive labels with tested adhesive performance (peel strength, heat resistance, UV resistance per the expected service environment) are acceptable where direct marking of the housing is not feasible. Document the marking method and the rationale for material selection in the technical file. 07 Affix the CE marking on the product packaging. For retail consumer products, the outer retail box must carry the CE mark. The mark size on the retail packaging should be at least 5mm height — there is no reason to use the minimum on packaging where space is not constrained. The CE mark on packaging is typically grouped with other mandatory information: manufacturer name and EU address, EU importer name and address, model reference, WEEE symbol, and barcode. Ensure that the NB number (if required) appears beside the CE mark on the packaging as well as on the product. 08 Issue and retain the EU Declaration of Conformity. The DoC must identify the product (including model numbers and any variants it covers), list all directives for which CE marking is affixed, reference the harmonised standards applied, identify the Notified Body and certificate number where applicable, and be signed by the person authorised to do so on behalf of the manufacturer. The DoC must be available to market surveillance authorities on request and must be retained for 10 years from the date of last placing on the market. For products sold online, the DoC or a link to it must be available to consumers. ## Frequently asked questions ### What is the minimum size for a CE mark? The minimum height for CE marking letters is 5mm, as specified in the EU Blue Guide 2022 (section 4.4) and in the annexes of product directives including LVD 2014/35/EU and RED 2014/53/EU. This applies to the height of the capital letters 'C' and 'E'. The proportions between the CE letters must be maintained — you cannot squish or stretch the mark. For small devices or components where it is technically impossible to affix a 5mm mark, the minimum can be reduced, but the mark must then appear on the product packaging and in accompanying documentation. There is no absolute lower limit stated in the legislation — the mark must be as large as possible given the size constraint, and must remain legible. Marks below approximately 3mm become very difficult to verify without magnification and regularly attract market surveillance scrutiny. ### Does the CE mark need to go on both the product and the packaging? The CE marking must be affixed to the product. Where it is not possible to affix it to the product, it goes on the packaging, and if not possible on the packaging, then on the accompanying documents. This is a defined hierarchy — each step requires demonstrating why the previous option was not possible. In practice for retail electronics, the CE mark appears on both the product itself (often near the rating label or model number plate) and on the retail packaging (typically on the back panel alongside the barcode, manufacturer address, and other regulatory markings). Having the mark only on packaging when the product physically could carry it is non-compliant and is a finding that market surveillance authorities act on. ### When must the Notified Body number appear next to the CE mark? The NB number — a four-digit designation number such as 0197 (BSI) or 0120 (TÜV Rheinland) — must appear immediately after the CE marking whenever a Notified Body was involved in the product's conformity assessment. This applies when the conformity assessment procedure required NB involvement: for example, Module B (EC type examination), Module D (production quality assurance with NB), Module F (product verification), or Module H (full quality assurance system certified by NB). When the manufacturer self-declares conformity using Module A — as is the case for many LVD and EMC products — no NB was involved and no NB number appears after the CE mark. The NB number is not optional when it is required; its absence on a product that required NB involvement is a nonconformity that can result in a market surveillance action or product halt. ### Can a CE mark be applied as a label rather than engraved or printed? Yes, an adhesive label is an acceptable method of affixing the CE mark provided it meets the permanence and indelibility requirements. The label must remain clearly legible and firmly affixed throughout the foreseeable lifetime of the product under normal use conditions. Labels that peel easily, that can be removed cleanly without evidence of tampering, or that will degrade under expected environmental conditions (moisture, elevated temperature, UV exposure, chemical contact) do not meet the permanence requirement. For products intended for industrial or outdoor environments, laser etching, engraving, or embossing are preferable. The EU Blue Guide does not mandate the method of application — it mandates the outcome: a visible, legible, and indelible marking that survives normal product use and handling. **Disclaimer:** Educational resource only. Regulatory requirements change. The EU Blue Guide is updated periodically and individual directive annexes take precedence over the Blue Guide where they differ. Consult a qualified compliance specialist before making marking decisions for your specific product and applicable directives. 🇪🇺 CE Marking roadmap for your product Every standard, document, and test that applies — free, no account required. 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