How to Read Hallmarks and Stamps: Sterling, EPNS, IS, 925

#110 The Lane We’re In (For This One)

We’re decoding the usual suspects—STERLING, 925, EPNS, IS, and friends—so you can tell sterling from plate fast on flatware and jewelry. We’re not getting into cleaning or tarnish care here (save your elbow grease). For that, you'll find “How to Clean Silver Safely at Home Without Ruining Patina” and “What Causes Tarnish and Why It’s Not a Flaw” coming to our blog soon.

The Fast Answer

When you see STERLING or 925, you’re looking at solid sterling silver, meaning the metal is 92.5% pure silver with 7.5% other metals. EPNS tells you the piece is electro-plated nickel silver—a base metal alloy with a thin silver coating, not solid silver. An IS stamp on flatware is usually the maker’s mark of International Silver Company and does not by itself guarantee sterling; you have to look for “Sterling” or “925” alongside it. The easiest way to read any hallmark is to break the mark into three questions: “What’s the purity mark, what’s the maker mark, and does anything here actually say silver?”

TL;DR

• STERLING / 925 = solid sterling silver, 92.5% pure silver. In the U.S., quality marks aren’t mandatory, but if used they must be accurate (≥925 parts per thousand silver) and are generally paired with a responsible maker/importer mark under U.S. marking rules and FTC guidance.
• EPNS / EP / EPBM = silver-plated wares (not solid). EPNS is plated over nickel silver; EPBM is plated over Britannia metal (tin-based alloy).
• IS = International Silver Company maker mark, used on both sterling and plated pieces; you must find “Sterling” or “925” to confirm purity.
• True hallmarks (e.g., British lion passant, town, date letters) are official assay marks; many plated pieces use “pseudo-hallmarks” that only look official.
• Start by finding the purity mark, then the maker, then any country symbols; if you only see EP/EPNS/A1/IS without “Sterling/925,” assume silver plate.
• For tricky or old marks, cross-check with a reliable reference (like Jackson’s Hallmarks or major museum/library guides) before you list, scrap, or heavily polish anything.

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The Basics: What a “Hallmark” Actually Is

Hallmarks are tiny stamped symbols that tell you the metal purity, who made the piece, where it was tested, and often the year it was assayed. In classic hallmarking systems (like Britain’s), these are applied by an official assay office, not by the manufacturer alone.

In contrast, many silver-plated pieces use “pseudo hallmarks”—little shields and symbols that look official but actually just spell out EP, EPNS, or similar plating codes. A quick mental shortcut: if you’re seeing cute fake-looking stamps but no clear purity mark (like 925 or a lion passant), you’re probably in silver-plate territory.

Three questions to ask every stamp

1. Purity: Is there anything that clearly states silver fineness, like “925,” “Sterling,” or a known official purity symbol?
2. Maker: Are there initials or a logo you can trace to a specific manufacturer (e.g., “IS” for International Silver Company)?
3. Extras: Do you see letters like EP, EPNS, A1, or decorative pseudo-hallmarks that suggest plating rather than solid silver?

If you can answer those three, you can usually figure out whether a piece is sterling, silver plate, or just “silver-tone.”

Sterling and 925: Solid Silver Marks

What “925” and “Sterling” mean

A 925 stamp or the word STERLING indicates sterling silver: an alloy that is 92.5% pure silver and 7.5% other metals (usually copper). In U.S. practice, sterling must be at least 925 parts per thousand silver; FTC jewelry guidance and U.S. marking rules reinforce that quality marks must be truthful and generally appear with a responsible maker/importer mark.

You’ll see these marks in a few common forms:

• “STERLING” (sometimes “STERLING SILVER”) on flatware and hollowware.
• “925” on jewelry shanks, clasps, or the back of pendants.
• Combination marks like “925 ITALY” or “925 THAI,” which tell you both purity and country of origin.

How to spot sterling in different regions

• U.S. / North America: “Sterling,” “925,” sometimes along with a maker’s trademark to comply with hallmarking laws.
• U.K. / Commonwealth: Look for official assay marks (e.g., the lion passant for sterling in many British systems) plus additional symbols for office and date.
• Modern global jewelry: “925” is the default short code for sterling on imported jewelry.

If a piece says Sterling or 925 and there is no EP or EPNS anywhere nearby, you’re firmly in the sterling camp.

One caveat: marks can be faked or misleading—especially on modern jewelry—so if the piece is high-value or you’re unsure, verify with a trusted reference or a professional before you buy, scrap, or refinish it.

EPNS and Friends: When You’re Dealing with Silver Plate

What EPNS actually stands for

EPNS means Electro-Plated Nickel Silver. In plain English, the core metal is a nickel-based alloy (often nickel, copper, and zinc) with no actual silver in it until a very thin layer of real silver is electroplated on top.

Nickel silver became popular as a base metal after the 1840s because it’s bright, strong, and visually close to silver, especially once plated. That’s why so much everyday “hotel silver” and mid-century flatware carries EPNS marks: it gave people the look of silver without the sterling price.

Common plating codes to recognize

If you find any of these, you’re in plated territory:

• EP – Electro-plate.
• EPNS / E.P.N.S. – Electro-plated nickel silver.
• EPBM – Electro-plated Britannia metal (a tin-based alloy).
• A1 / B1 – Plating quality codes sometimes used with silver plate; A1 commonly indicates a higher grade within a maker’s system, while other codes (like B1) vary by manufacturer. Either way, they still mean plate, not sterling.

Guides for collectors and libraries note that seeing EP, EPNS, or similar marks is a reliable sign you’re looking at silver plate, not solid sterling.

Pseudo-hallmarks on plate

Manufacturers of plated cutlery often created strings of tiny symbols that resemble official hallmarks but actually just encode EP/EPNS or branding. These pseudo-hallmarks can mislead new collectors at a glance, so always scan them for tell-tale letters like EP, EPNS, or A1.

If you decode the symbols and never find “Sterling,” “925,” or a recognized standard mark, assume plate first.

IS and Maker Marks: The Tricky Middle Ground

What does “IS” mean on flatware?

On American flatware, IS is widely used as a mark of the International Silver Company, a large silver manufacturer founded in Meriden, Connecticut in 1898. It’s a corporate or maker’s mark—basically a brand stamp—not a purity guarantee.

You’ll often see “IS” combined with pattern names and other words, such as “Rogers & Bros IS” or similar, on both sterling and silver-plated lines. Because of that, you cannot treat “IS” as shorthand for sterling; you still have to look for “Sterling” or “925.”

(On jewelry, “IS” can also be unrelated initials, so treat it as a maker-style clue—not a metal guarantee.)

How to interpret IS in real life

• “Sterling IS” or “Sterling” plus IS: Indicates sterling silver made by, or under, the International Silver umbrella.
• Pattern name + IS, but no “Sterling/925”: Very often a silver-plated pattern.

Treat “IS” like a surname: it tells you who, not what. The purity question still has to be answered separately by other marks.

How to Read a Hallmark Step by Step

Guides from experienced silver specialists recommend a simple sequence: find the mark, identify the standard (purity) symbol, then parse maker and date.

Step 1: Find every mark

Look on the back of flatware handles, the underside of bowls and trays, or inside ring shanks and near jewelry clasps. Marks are usually on a flat, relatively protected area. Wipe gently with a soft cloth so you’re not reading through tarnish.

Step 2: Identify the purity clue

Ask: “Is there anything here that clearly states fineness?”

• Sterling clues: “Sterling,” “925,” lion passant, or similar standard marks.
• Plating clues: EP, EPNS, EPBM, A1, B1, or just obviously pseudo-hallmark strings.
• No purity words at all: treat with suspicion until proven otherwise.

Step 3: Separate maker from metal

Maker marks are initials, logos, or company names (e.g., “IS,” “Rogers,” etc.). They tell you who made the piece and can hint at quality and age, but they don’t automatically indicate sterling unless that company only produced sterling in that line.

If you’re unsure, cross-check the maker stamp against a reputable pattern or mark database used by collectors or museums.

Step 4: For British-style hallmarks

If you have a full British hallmark set—standard mark, assay office, date letter—use a guide that walks through each symbol in order. A common approach is:

1. Standard mark (lion passant for sterling in many British systems).
2. Town mark (e.g., Birmingham anchor, London leopard’s head).
3. Date letter (year code).
4. Maker’s mark (initials in a shaped punch).

(Scottish marks vary by assay office and period—often featuring a lion rampant; Edinburgh historically used a thistle in certain eras—so decode the full set rather than relying on one symbol.)

Reference handbooks like Jackson’s Hallmarks are strongly recommended by professional dealers for decoding these systematically.

Quick-Reference Hallmark Table

Stamp / clue	What it usually means	Sterling or plate?	What to do next
STERLING	Sterling silver, 92.5% pure silver.	Sterling	Confirm with context (country, maker); safe to treat as solid silver.
925	Sterling fineness, 92.5% silver, common on jewelry.	Sterling	Look for additional marks (country, maker) near it.
Lion passant (U.K.)	Official British sterling standard mark.	Sterling	Use town + date letter charts to pinpoint age.
EP / EPNS	Electro-plated nickel silver (no solid silver core).	Plate	Assume plated; value is in design/condition, not silver weight.
EPBM	Electro-plated Britannia metal.	Plate	Treat as plate; silver content is in the coating only.
A1 / B1 with silver plate	Manufacturer quality designations on plate; A1 commonly indicates a higher grade within that maker’s system, while other codes vary.	Plate	Still plate; treat as plated unless “Sterling/925” appears.
IS (on flatware)	International Silver Co. maker mark.	Either	Look for “Sterling/925”; without them, assume plate.
No purity mark, only fancy symbols	Often pseudo-hallmarks for plate.	Usually plate	Check carefully for hidden EP/EPNS; if none, research before assuming sterling.

 

From the VGA bench

We handle vintage silverware and silver-tone flatware every week, and the pattern is almost always the same: the pieces people hope are sterling are often EPNS with very convincing pseudo-hallmarks. The ones that quietly say “Sterling” or “925” are usually hiding in the back of the drawer, tarnished and ignored, because they don’t shout. Our rule in the studio is simple—if a piece doesn’t clearly tell you it’s sterling, you have to treat it like silver plate until you’ve done your homework. It’s gentler on your expectations and your polishing arm.

Key Hallmark Types You’ll See Most

Purity marks (tell you the metal)

• Sterling / 925: Indicates sterling silver quality; in U.S. practice, 925 parts per thousand must be met for a piece marketed as “sterling,” and if a quality mark is used it must be truthful (and typically appears with a responsible maker/importer mark).
• Higher or lower fineness marks: Some pieces, especially European, may display other numbers (e.g., 800 for 80% silver) rather than 925.
• No numeric mark at all: On older or non-Western items, purity may be indicated by symbols instead of numbers, which makes a reference guide essential.

Maker’s marks (tell you who)

Maker’s marks are the silversmith’s or company’s “signature”—initials, logos, or names in a small punch. In some jurisdictions, when a purity mark is used, the maker’s registered mark has to appear nearby to comply with stamping laws.

IS is one example: it flags the International Silver Company, whose patterns are popular with collectors even when plated. Other makers have their own initials or symbols, so a good marks dictionary is your best friend when you’re stumped.

Assay and town marks

In countries with official hallmarking systems, you may also see:

• A town mark (e.g., Birmingham’s anchor).
• A duty or tax mark on certain periods of British silver.
• A date letter indicating the year the piece was assayed.

These marks don’t change the metal content, but they matter for dating and valuing a piece.

When You’re Still Not Sure

Even careful hallmark reading sometimes leaves question marks, especially on worn or obscure pieces. Reputable guides emphasize a few “next steps” before you make any big decisions:

• Cross-check multiple sources: Use at least one recognized hallmark handbook or museum/library guide, not just random image searches.
• Consider getting a professional opinion: Longtime dealers and appraisers work with silver every day and can often recognize patterns and marks quickly.
• Avoid destructive testing: Since silver plating is thin, aggressive filing or acid testing can permanently damage both sterling and plate; expert guides urge caution.

If you’re planning to sell, scrap, or heavily refinish a piece, it’s worth verifying the marks before you do anything irreversible.

Key Takeaways

• “Sterling” or “925” means sterling silver at 92.5% purity; in U.S. practice, that 925 threshold is built into truth-in-marking standards for sterling quality marks.
• EPNS, EP, EPBM, and related codes clearly indicate silver-plated wares rather than solid silver.
• IS is a maker mark (International Silver Company), not a metal guarantee; always look for an accompanying sterling or 925 mark.
• True hallmarks from official assay systems follow a structured code (standard, town, date, maker), while pseudo-hallmarks on plate just mimic the look.
• When in doubt, treat ambiguous pieces as plate until a reliable reference or expert tells you otherwise.

FAQ

Is 925 always sterling silver?

Yes, a 925 stamp indicates that the alloy is 92.5% pure silver, which is the standard definition of sterling silver in many markets, including the United States.

Does EPNS have any solid silver inside?

No; EPNS is a base metal alloy (nickel silver) with a thin layer of silver plated on top, and the core contains no elemental silver until it is plated.

If my flatware only says IS, is it sterling?

Not necessarily. IS is a mark of International Silver Company and appears on both sterling and plated lines, so you must find “Sterling” or “925” nearby to confirm solid silver.

Are A1 and B1 better than EPNS?

A1 is commonly used as a higher-grade designation within a maker’s silver-plate system. Other codes (like B1) vary by manufacturer, but they still indicate plate—meaning the underlying metal is plated, not sterling.

How can I tell solid silver from plate at a glance?

Solid silver usually carries a clear fineness mark (Sterling, 925, lion passant, etc.), while plate uses EP/EPNS and pseudo-hallmarks.

Why do some British-style marks look official but aren’t sterling?

Many manufacturers of plate created pseudo-hallmarks that mimic official assay marks; these strings often include EP or EPNS and lack any true standard mark.

Are there legal rules about using sterling marks?

Yes. In U.S. practice, to mark an item as “sterling,” the silver content must be at least 925 parts per thousand, and if a quality mark is used, a responsible maker/importer mark typically must appear with it.

Parting Words

If you love the look of old silver but don’t want to memorize every mark, the safest route is often to let someone else do the hallmark decoding. A curated spoon-ring or vintage-flatware jewelry collection built from verified sterling and well-chosen plate lets you enjoy the patterns you love without stressing over every EPNS versus 925 stamp. When you’re shopping patterns or picking a gift, use the same three questions—purity, maker, and extras—and look for makers who clearly label their sterling and silver-plate pieces in the description, not just in tiny letters on the back.