Roman Coin Mint Marks: Identify the Mint from the Exergue

Mint mark: look in the exergue, the strip below the reverse design. Enter the letters exactly as seen.

Quick Answer

A Roman mint mark is the short string in the exergue — the strip below the reverse design. Read it in three parts: an optional prefix (SM sacra moneta, M moneta), the mint-city abbreviation (TR Trier, SIS Siscia, ANT Antioch, K Cyzicus), and an officina (workshop) letter — Latin P S T Q in the West, Greek Α Β Γ Δ in the East. Coins struck before Diocletian's reforms (c. 294 AD) usually carry no mint mark and are attributed by style.

Where to look: the exergue

The mint mark sits in the exergue — the strip below the reverse design, under the ground line. Read it left to right as prefix, mint city, then officina.

Diagram of a Roman coin reverse showing the exergue A circle stands for the coin. A horizontal ground line divides the main reverse design above from the exergue strip below, where the mint mark is struck. Reverse design SMKΒ Exergue — the mint mark sits here

The mark above reads left to right: prefix (SM, sacra moneta), mint city (K, Cyzicus), officina (Β, second workshop).

Every Roman mint and its marks

Type a mark in the decoder above to narrow this table, or browse all 23 mints below.

MintMarksOfficinaActive
AlexandriaAlexandria, Egypt SM · AL · ALE · ALEX Greek (Α Β Γ…) 294–476 AD
Amiens (Ambianum)Amiens, France AMB · AMBI Latin (P S T…) 350–353 AD
AntiochAntakya, Türkiye SM · AN · ANT · ANTOB Greek (Α Β Γ…) 294–476 AD
AquileiaAquileia, Italy SM · AQ · AQVIL Latin (P S T…) 294–425 AD
Arles (Arelate)Arles, France AR · ARL · CON · CONST · KON Latin (P S T…) 313–475 AD
Barcelona (Barcino)Barcelona, Spain SM · BA Latin (P S T…) 409–411 AD
Carthage (Carthago)Carthage (near Tunis), Tunisia K · KART Latin (P S T…) 296–307 AD
ConstantinopleIstanbul, Türkiye CONS · CONSP · CP Greek (Α Β Γ…) 326–476 AD
CyzicusErdek, Türkiye SM · M · K · KY · CVZ · CYZ Greek (Α Β Γ…) 260–475 AD
Heraclea (Thracica)Marmara Ereğlisi, Türkiye SM · HT · HERAC · HERACL Greek (Α Β Γ…) 291–476 AD
London (Londinium)London, England P · M · LN · LON · AVG · AVGOB Latin (P S T…) 296–388 AD
Lyon (Lugdunum)Lyon, France P · LG · LVG · LVGD Latin (P S T…) 274–413 AD
Milan (Mediolanum)Milan, Italy MD · MED · MDOB Latin (P S T…) 364–475 AD
Nicomediaİzmit, Türkiye SM · M · N · NIC · NIK Greek (Α Β Γ…) 294–476 AD
OstiaOstia, Italy M · P · OST Latin (P S T…) 308–313 AD
RavennaRavenna, Italy RV · RAV Latin (P S T…) 404–476 AD
RomeRome, Italy SM · R · RM · ROM · ROMA Latin (P S T…) 294–476 AD
SerdicaSofia, Bulgaria SM · SD · SER · SERD Greek (Α Β Γ…) 272–314 AD
SirmiumSremska Mitrovica, Serbia SIRM · SIR Latin (P S T…) 320–395 AD
SisciaSisak, Croatia SIS · SISC Latin (P S T…) 262–387 AD
ThessalonicaThessaloniki, Greece SM · TES · TS · THES Greek (Α Β Γ…) 298–476 AD
TicinumPavia, Italy SM · T · TIC Latin (P S T…) 274–326 AD
Trier (Treveri)Trier, Germany SM · TR · TRE Latin (P S T…) 294–430 AD

Reading officina letters

Western mints number workshops with Latin letters: P prima (1), S secunda (2), T tertia (3), Q quarta (4). Eastern mints use Greek letters: Α 1, Β 2, Γ 3, Δ 4.

When and why mint marks began

Regular exergual marks appear from the mid-3rd century and were standardized under Diocletian's reforms around 293–294 AD, giving the state control over which mint and workshop struck each coin.

My coin has no mint mark

Coins struck before the late 3rd century usually carry no exergual mark. They are attributed by portrait style, fabric, and legend, cross-referenced with RIC. See how to identify Roman coins for the full method.

Frequently asked questions

Where is the mint mark on a Roman coin?

In the exergue — the strip below the main design on the reverse.

What do the letters SM and M mean?

SM stands for sacra moneta and M for moneta; they are prefixes marking the mark as an imperial mint signature.

What is an officina letter?

The officina is the workshop within a mint. Western mints number them with Latin letters (P, S, T, Q = 1st–4th); eastern mints use Greek letters (Α, Β, Γ, Δ).

When did Roman coins start having mint marks?

Regular exergual mint marks appear from the mid-3rd century and were standardized by Diocletian's reforms around 293–294 AD.

What if my coin has no mint mark?

Most coins before the late 3rd century carry no mint mark; the mint is attributed from portrait style, fabric, and legend, cross-referenced with RIC.

Have the coin in front of you? Identify it with catalog search.