What are channel letters? A buyer's guide

The International Sign Association (ISA) defines a channel letter as “A three-dimensional letter that may include a light source.” A set of channel letters spells a name or a logo, and each letter is a separate unit fixed to the wall or to a raceway. A lit name made of separate letters, with no box around it, is a channel letter sign.

This guide is for a buyer who orders channel letters from a manufacturer, in the same country or another one. It names the parts, the lighting types and the mounting methods, then covers listing, marks and power supplies in the US, the UK, the EU and Australia, and ends with a checklist that makes quotes comparable. The sizes in the parts table are what two named US makers publish. They are examples, not standards.

01 What channel letters are

A channel letter is a fabricated hollow letter. Sign Fab describes the build: a 3 to 6 in strip of aluminium sheet is bent around an aluminium back to form the sides, and acrylic or polycarbonate is cut to fit the face. The hollow inside holds the LED modules and the wiring. A letter without lighting has the same shell and no electrical parts.

The fabricated shell is what separates channel letters from three neighbouring products.

• Dimensional letters are cut from solid or flat material rather than built as a shell. They are usually unlit.
• Lightbox signs and cabinet signs put the whole message on one lit panel inside a box. With channel letters, only the letters are built, and the wall shows between them.
• Edge-lit acrylic signs and LED signs are different products on Find Sign Makers. If a quote for letters uses either name, ask for a drawing of the construction.

The types of business signs guide places channel letters among the other sign types by where they go and what they do. The channel letters page lists the manufacturers on Find Sign Makers that make them. The rest of this guide stays on channel letters and what to specify when you order them.

02 The parts of a channel letter

A channel letter has four structural parts (face, returns, trim cap and back) and, when lit, two electrical parts (LED modules and a power supply). A raceway or a wireway is added when the letters do not mount directly to the wall.

Two US makers publish part sizes: Sign Fab and Sign Leaders. The table shows what each one quotes. Their figures differ, which is the point: there is no single standard depth, thickness or trim width, so the quote must state the figure.

Return depth is where the two makers differ most: Sign Fab gives 5 in as its standard and Sign Leaders a range of 3 to 5 in. Ask the maker which depth it proposes for your letter height and lighting type, and get the figure in the quote.

The electrical parts are the hardest to compare from a quote, because two sets of letters can look the same and use different modules and power supplies. Ask each maker to name the module and the power supply it will fit, with the voltage of each. Two quotes for the same letters with different modules are quotes for two different signs.

03 Types of channel letters by lighting

Channel letters are sorted by where the light leaves the letter. The lighting type changes the look, the build, what the wall must be like and the price, so name it in the brief.

Front-lit letters

Front-lit letters shine light out through the face, so the face itself glows. The face colour commonly comes from coloured acrylic or from a translucent film on a white face. Ask for the face material and colour, and ask for a sample or a photograph of the colour lit, because a colour can look different at night.

Halo-lit letters

The ISA glossary describes a backlighted letter as a channel letter with an open or translucent back that is illuminated, so that the light shines onto the surface behind it and produces a halo effect. It also defines a reverse channel letter as a letter mounted away from a wall, forming a halo behind it. Makers often use “halo-lit”, “reverse-lit”, “back-lit” and “reverse channel letters” for the same product, so ask where the light leaves the letter and whether the face is lit.

Wikipedia gives the usual stand-off from the wall as about 1 1/2 in (about 38 mm). In the channel letter cost guide, the halo-lit band starts and ends higher than the front-lit band, though the bands overlap and front-and-back lit sets are banded higher again. The glow falls on the wall, so the wall surface and colour become part of the sign. Put the wall material and finish in the brief and ask for a rendering on your wall. The halo-lit letters page lists makers that name this type.

Front-and-back lit letters

Front-and-back lit letters, also called combination-lit, light through the face and out of the back at the same time. The face glows and a halo forms on the wall. The build usually pairs a lit face with an open or clear back, and the letters stand off the wall. The quote should state how each side is lit and the stand-off distance.

Open-face letters

The ISA glossary defines an open channel letter as a letter with no face, though a clear face may be used to protect the components. When it is lit, the light source can be seen. Ask whether a clear face is fitted, how the modules are protected from the weather, and which rating the exposed parts carry.

Trimless letters

Makers use the term trimless for letters without a visible trim cap around the face. Buyers search for them by that name. Ask the maker how the face is held, what edge shows from the front and from the side, and whether a face can be replaced without damage.

Non-illuminated letters

Non-illuminated channel letters have the same shell as a lit set, with no modules and no power supply. Sign Fab states that UL codes do not apply to non-illuminated signs. Local rules on sign size and position still apply, so the permit step stays in the plan.

04 How channel letters are mounted

Makers commonly mount channel letters in one of three ways: on a raceway, on a wireway, or flush to the wall with the power supplies behind it. The method decides where the power supplies sit, how many holes go into the wall, and how a technician reaches the parts later.

Raceway

A raceway is a metal enclosure fixed to the wall. The letters mount to it, and the wiring and power supplies sit inside it. In Sign Fab’s comparison of mountings, a raceway needs fewer mounting holes in the wall than flush-mounted letters, and a technician services it by removing the top. A raceway shows on the wall, so its colour goes in the brief. Sign Leaders lists raceway wiring with a primary lead and a disconnect switch. Ask whether the quote includes both.

Wireway

A wireway is a shallower channel that carries the wiring only. Sign Fab gives about 2 in of depth, with the power supplies inside the wall. A wireway is shallower than a raceway, and Sign Fab notes that it can double as a backer. If you want a backer panel, state its size, material and colour.

Flush mounting with remote power supplies

With flush mounting, sometimes called remote mounting, each letter is fixed to the wall on its own and the power supplies sit behind the wall. Nothing shows between the letters. In return, the wall needs an opening behind each letter for the wires and a place inside for the power supplies. Find out what the wall is made of and who will make and seal the openings before you choose this method.

Mounting patterns

Some makers, including ChannelLetter.com, supply a full-size (1:1) paper pattern with each set. It shows every fixing hole and wire opening. The installer tapes it level on the wall, drills through it and removes it. A remote buyer depends on the pattern, because the installer has never seen the letters before they arrive. Ask for it in the quote, and ask whether it covers the raceway as well as the letters.

05 Electrical listing and inspection in the US

UL 48 is the US standard for electric signs. UL Standards & Engagement states that it covers all electric signs, art forms and outline lighting used under NFPA 70, the National Electrical Code (NEC), regardless of voltage and including LED signs. As of 21 October 2026, the listing shows edition 15, revised 14 May 2025.

Listing applies to the finished sign

In most US jurisdictions, the inspector looks for a listing mark on the finished sign. Listed LEDs, power supplies and wire inside the letters do not, on their own, make the sign listed. Wholesale Sign Pro explains that the mark is normally applied at the factory by a manufacturer authorised under the certification programme, and that a field evaluation covers only the sign examined. Sign Fab states that it cannot list a sign whose lighting is added after manufacture without an on-site UL inspection.

The authority having jurisdiction (AHJ), usually the city or county building department, decides what it accepts. A mark from another nationally recognised testing laboratory with UL 48 in scope, such as ETL or CSA, may be accepted. Ask the inspector which marks are accepted before you order, and ask the maker which mark it will apply, under which programme.

The July 2024 marking change

UL changed how channel letter signs are marked from 1 July 2024. An ISA member alert of 28 August 2024 explains the change. Letters that are connected only by Class 2 field wiring, the low-energy wiring between the power supply and the modules, now count as one sign in several housings. That sign may carry one UL “Electric Sign” mark on the raceway or on the enclosure that holds the power supply. Each letter no longer needs its own “Sign Section” mark.

The alert warns that inspectors who have not heard of the change may fail a correctly marked sign because the letters carry no mark of their own. ISA advises giving the AHJ a copy of the alert, or asking the AHJ to confirm the change with UL. If you buy from a maker outside your area, ask the maker to state where the mark will sit and how the letters are wired, and give that information and the alert to your electrician before the inspection.

The NEC and the disconnect

The NEC’s Article 600 requires electric signs to be listed and installed to their listing, and requires a disconnecting means for each sign circuit. Cities adopt different editions of the NEC, so the electrician works to the edition your city uses. Ask whether the maker fits the disconnect switch on the raceway or whether your electrician supplies it.

06 Power, marks and ratings outside the US

Outside the US, the mains voltage is the first thing that changes. The IEC World Plugs list gives US mains as 120 V at 60 Hz, and the UK, Australia and EU countries as 230 V at 50 Hz. A power supply is rated for an input voltage range and a frequency. Ask the maker to state both in the quote and to confirm that they cover the mains in the delivery country.

CE and the Low Voltage Directive

In the EU, the Low Voltage Directive 2014/35/EU has applied since 20 April 2016 to electrical equipment with an input or output of 50 to 1000 V AC or 75 to 1500 V DC. A sign fed from 230 V mains falls inside that range. The European Commission states that the CE marking may be affixed only after a conformity assessment.

A CE mark on a factory web page does not show what it covers. Ask the maker which marks the letters will carry and ask for the declaration of conformity or the certificate. Check whether the document covers the sign, the power supply, or both.

UKCA and CE in Great Britain

GOV.UK guidance on the UKCA marking lists the Electrical Equipment (Safety) Regulations 2016 and the Electromagnetic Compatibility Regulations 2016 among the regulations under which a maker can declare UKCA conformity. The same guidance says that Great Britain continues to recognise CE marking, alongside or in place of UKCA, for many products. Ask the maker which mark it applies and for the document behind it.

RCM in Australia

In Australia, the Regulatory Compliance Mark (RCM) shows that electrical equipment meets electrical safety and electromagnetic compatibility requirements. Under the EESS scheme, equipment is registered by an Australian or New Zealand responsible supplier, not by an overseas factory. Ask who will fill that role for your letters.

IP ratings for outdoor letters

The IP code comes from IEC 60529. IP65 means dust-tight and protected against low-pressure water jets. IP67 means dust-tight and protected against temporary immersion, to 1 m for 30 minutes. A rating applies to the part that was tested, such as a module or a power supply, not to the whole letter. A letter is a fabricated shell, not a sealed box, so ask which parts carry which rating and how water drains out of the letters.

Find Sign Makers does not verify certifications or marks. Check any document with your electrician, inspector or local authority.

07 Permits and landlord approval

Approval rules for building signs are local, and a maker in another city cannot apply for a permit on a site it has never seen. Ask the local authority which approval applies to a lit sign on your building, and what it needs with the application, before you order. The sign permits guide explains who can apply and which documents to get from the maker.

In the US, ask the city or county building department whether it wants drawings, the listing documents, or both, and whether it treats lit and unlit letters differently.

In England, Planning Portal lists the majority of illuminated signs among the adverts that normally need advertisement consent. Some adverts have deemed consent, depending on their size, position and lighting, so a lit channel letter sign may or may not need an application. Ask the local planning authority. Rules elsewhere differ, so ask the planning office where the sign will go.

A landlord can add a second layer. A lease or a set of tenant sign criteria may fix the letter height, the colours, the lighting type and where a raceway may run. Get the criteria before you pay for artwork, then ask the authority, then order.

Permit drawings, freight, installation and the electrical connection are often separate lines from the letters. The channel letter cost guide lists the costs that sit around the letters. Ask each maker which of them its quote covers.

08 Buying from a manufacturer or a local sign company

A manufacturer makes the letters, the raceway and, often, the mounting pattern. A local sign company usually also handles the permit, the drawings, the installation and later service. Some wholesale makers sell to sign companies, which do the local work themselves. The steps that decide whether the sign is accepted, the permit, the listing and the inspection, all happen where the sign is fitted.

When a local sign company suits better

A local sign company is usually the better choice in four cases:

• A one-off job. Arranging the permit, the installer and the electrician yourself can cost more than you save on the letters.
• A strict authority. A company that has passed inspections in your city knows what the inspector asks for.
• A difficult wall. Flush mounting needs openings behind each letter, and a local company can survey the wall before it quotes.
• Fast service. A remote maker usually cannot repair a failed power supply on site.

A manufacturer can suit a large set, a repeat order across several sites, or a sign company that already has installers and electricians, provided the buyer arranges the local steps.

What a remote buyer arranges locally

When the maker is in another city or country, the buyer takes on five tasks:

• Permit. Find out which approval applies, who applies for it, and which documents it needs.
• Installer. Book someone to fix the pattern, drill the wall and mount the letters.
• Electrician. Book a licensed electrician to connect the sign circuit and the disconnect, to the local rules.
• Inspection. Ask when the authority inspects, which marks it accepts, and who must be present.
• Service. Agree who replaces a failed module or power supply, how it is reached, and where spare parts come from.

Put these tasks in the plan before you order, and ask the maker which of them it can help with.

09 What to put in your channel letter brief

A quote is only as comparable as the brief behind it. Wholesale makers such as Wholesale Sign Superstore and Direct Sign Wholesale ask for the same core: letter height, stroke width, overall length, artwork or font, the wording, colours, the mounting method, lit or unlit, and whether UL labels are needed. This checklist adds what a buyer ordering from a distance also needs.

1. Wording and quantity. Give the exact text and the number of sets, and say whether each site needs the same set.
2. Artwork. Attach vector files for the logo and name the font.
3. Letter height. Give the height of the tallest letter, and of the lower-case letters if any, in inches or millimetres.
4. Stroke width. State the width of the letter strokes, which makers ask for with the height.
5. Overall length. Give the width of the whole set and say whether it must fit a fixed space on the wall.
6. Face. State the face material, its thickness and the face colour or film, with a colour reference.
7. Returns and trim cap. State the return colour, ask the maker to state the return depth, and give the trim cap colour and width, or trimless.
8. Lighting type and LED colour. State front-lit, halo-lit, front-and-back lit, open-face or unlit, and the light colour.
9. Mounting. State raceway, wireway or flush, with the raceway size and colour and any backer panel.
10. Wall. Name the wall material and finish, add a photograph, and say whether there is access behind it.
11. Modules and power supplies. Ask the maker to name the module and power supply models, their voltages, and where the power supplies will sit.
12. Mains supply. State the mains voltage and frequency at the site, and ask the maker to confirm that the power supplies are rated for it.
13. Listing or marks. State the listing or marks the sign needs in the delivery country, where the mark will sit, and which documents come with it.
14. Outdoor rating. State whether the letters go outdoors, and ask for the rating of the modules and power supplies.
15. Disconnect and primary lead. Ask whether the disconnect switch and the primary lead are fitted or left to your electrician.
16. Mounting pattern. Ask for a full-size pattern of fixing holes and wire openings.
17. Packing, freight and delivery country. Give the delivery address, and ask how the letters are packed, who handles freight and whether duties and taxes are in the price.
18. Installation, permit and timing. State who installs, who applies for the permit, and the date you need the sign.
19. Warranty and spare parts. Ask what the warranty covers and how a replacement module or power supply reaches the site.

Ask each maker to list what the quote includes and excludes: proofs, permit drawings, freight, duties, installation, the electrical connection and the warranty. Compare the scope before you compare the price. For a price frame, read the channel letter cost guide; its prices come from named third-party sources, not from Find Sign Makers; where it combines them, the arithmetic is ours. The signage RFQ template has a full brief you can copy and adapt.

10 How to send your brief on Find Sign Makers

Find Sign Makers is a directory, not a seller. It does not make, sell, price or ship signs. It lists manufacturers so that you can compare them and contact them.

1. Open the channel letters page, the channel letter manufacturers page or the wholesale channel letters page. To start wider, open all sign manufacturers.
2. Compare profiles. Check the sign types, the countries each maker ships to, and where it is based. These are separate facts, so do not assume one from the other. The delivery countries list shows which makers ship to your country.
3. Read the Verified badge for what it is. It means the directory holds a stored evidence record for the business and the profile scores at least 90 out of 100 for completeness. It is not an endorsement, and it does not confirm quality, pricing or certification. The verification criteria explain the rule.
4. Open a profile and send your brief from its quote form. The brief goes to that manufacturer and to up to two others that list the sign type and ship to your delivery country. It is free, and you do not need an account.
5. Compare the replies against your own brief, line by line. Each manufacturer owns its quote, its terms and its inclusions.

The manufacturer whose profile you use always receives the brief, so check first that its profile lists channel letters and ships to your country. Write the full brief with the signage RFQ template before you open the form.