Commercial waterproof festoon lights for contractors, venues and distributors. Custom E27/B22, 24V/230V and OEM/ODM outdoor string light systems for UK, EU and Australia projects.

jackygong@wendadeco.com+86 139 8930 6042

E27 vs B22: A Country-by-Country Lampholder Guide

2026-10-20

E27 is an Edison-screw cap, while B22 is a bayonet cap; they use different holder interfaces and are not interchangeable without a matching holder. For UK, EU and Australian projects, specify the cap required by the actual luminaire or replacement lamp—not by country name alone—and verify the lamp’s electrical and physical ratings as well.

E27 and B22 at a glance

E27 lamps screw into a matching Edison-screw holder. B22 lamps use a bayonet connection, with pins that engage slots in a matching holder. The cap type identifies the lamp-to-holder interface; it does not by itself confirm voltage, wattage, dimmer compatibility, enclosure suitability or regulatory compliance.

Project market	What the official references establish	Practical specification check
United Kingdom	BSI’s BS EN 61184 covers B15d and B22d bayonet lampholders. This establishes a relevant holder standard, not that every UK fitting uses B22.	Check the existing fitting or project schedule. If B22d is required, state it explicitly and confirm the replacement lamp’s electrical ratings.
European Union	IEC 60061 covers lamp caps and holders with gauges intended to support interchangeability and safety. It does not provide a simple country-by-country rule that every EU project uses E27.	Confirm the holder fitted at the installation site and the exact cap designation in the luminaire or bulb specification. Do not infer the cap from “EU” alone.
Australia	The Australian Government’s Energy Rating guide identifies B22 and E27 as cap types that fit corresponding socket sizes. It does not say one type is universal across Australia.	Confirm the installed holder, cap marking, voltage and lamp requirements. Where regulated supply is involved, verify applicable product compliance separately.

How to choose for a project

Inspect the holder or drawings. Record the cap marking from the existing lamp, luminaire documentation or approved bill of materials.
Specify the exact interface. Write “E27 Edison screw” or “B22/B22d bayonet” rather than only “standard bulb.”
Check the complete lamp rating. Confirm rated voltage, wattage, dimensions, temperature limits, dimming requirements and suitability for the fitting or environment.
Check the destination’s rules separately. A matching cap does not prove that the lamp or luminaire meets local electrical or product requirements.
Approve a sample where fit matters. Check insertion, retention, clearances and operation in the intended holder before ordering a project quantity.

Common procurement mistakes

Assuming a country has only one lamp-cap type.
Treating E27 and B22 as interchangeable because the lamps look similar.
Ordering by cap type without confirming voltage, wattage, dimensions or dimmer compatibility.
Confusing a lamp-cap standard with approval or certification of the complete lamp or luminaire.

Frequently asked questions

Are E27 and B22 interchangeable?

No. E27 screws into an Edison-screw holder; B22 uses a bayonet holder. Use the cap that matches the installed fitting, or replace the holder only through an appropriately qualified process.

Is B22 the standard for every UK project?

No. BSI publishes a standard covering B22d bayonet lampholders, but that does not establish that every UK fitting uses B22. Check the actual luminaire or project specification.

Does the EU use E27 instead of B22?

Do not assume that from the region name. Identify the holder at the installation site and specify the exact cap. IEC 60061 is an international reference for lamp caps and holders, not a country-by-country prevalence chart.

Which should I specify for Australia?

Specify the cap that matches the installed holder. Australian Government guidance lists both B22 and E27 cap types; confirm the fitting, electrical ratings and applicable compliance requirements for the product being supplied.

Does a matching cap mean the lamp is electrically suitable?

No. Cap fit is only one part of selection. Check voltage, wattage, physical clearance, heat conditions, dimming and the luminaire’s instructions.

What information should a B2B RFQ include?

Include the required cap type, lamp voltage and wattage, dimensions, quantity, destination market, intended fitting and any required documents. If the holder is not known, send a clear photo or drawing for confirmation before production.