Futures Month Codes: Decode the Contract Without Guessing Its Expiry

The complete letter table

CME publishes the following contract month codes. Their sequence is not a set of calendar initials, so decoding a letter from memory is an avoidable source of mistakes.

Standard futures contract month letters

Month	Code	Month	Code
January	F	July	N
February	G	August	Q
March	H	September	U
April	J	October	V
May	K	November	X
June	M	December	Z

The table identifies months, not the months available for every product. A contract can list monthly, quarterly or other cycles. Check the exchange's listing schedule for the precise product and year rather than assuming that all twelve letters correspond to active contracts.

Use the futures month-code decoder

The Futures month-code decoder separates a string written as ROOT + MONTH + YEAR, without separators. Enter the symbol, declare its product root separately, supply the full year when required, and choose Decode symbol. Reset example restores MESZ26, root MES and full-year context 2026. The result explains the string; it does not look up an exchange instrument.

This is one deliberately limited input format, not a universal vendor parser. CME's trading-code introduction explains the product/month/year components and warns that display conventions vary by platform. A brokerage system may use different roots, separators or instrument identifiers. Confirm its actual naming convention before translating anything.

The declared root may contain 1–16 ASCII letters or digits, including a digit at either end. For the symbol and declared root, the parser trims outer whitespace and treats ASCII lowercase letters as uppercase. Full-year context must contain exactly four digits, with no surrounding whitespace. It then requires that exact root, followed by one recognized month letter and a year suffix containing exactly one, two or four digits. Internal spaces, punctuation, exchange prefixes and three-digit year suffixes are outside this format.

Resolve the year instead of guessing a decade

A one-digit suffix needs a separately supplied four-digit year whose last digit matches. Thus MESZ6 with context 2026 resolves to December 2026; the same string with context 2036 resolves to December 2036. Neither interpretation is established by the final digit alone. The decoder does not choose the nearest year or use today's date.

A two-digit suffix works the same way using the last two digits. MESZ26 with context 2026 resolves to 2026, but 1926 and 2126 also end in 26. A context of 2027 conflicts and must be rejected. The full year is a declaration you must substantiate from the original record, instrument details or appropriate historical source.

A four-digit suffix is self-contained within this exercise: MESZ2026 supplies 2026 directly and does not require a context year. Accepted full years run from 1000 through 9999. That numerical range is a parsing boundary, not an exchange listing horizon. A syntactically valid year does not establish that the product existed then or will be offered in that year.

Original decoder examples; successful parsing confirms format and supplied context only, not a listed contract

Input symbol	Declared root	Full-year context	Named month and year
MESZ6	MES	2026	December 2026; one-digit year matched
MESZ26	MES	2026	December 2026; two-digit year matched
MESZ2026	MES	Not required	December 2026; explicit four-digit year
SR3U26	SR3	2026	September 2026; root ends with a digit
6EH26	6E	2026	March 2026; root starts with a digit
mesz26	mes	2026	December 2026 after outer-space and case normalization

The separate root field prevents a digit inside a product code from being casually treated as the year. It does not verify the root against a product directory. A made-up alphanumeric root can satisfy the grammar, so retain the exchange and product identity as separate evidence. The examples show parsing mechanics, not current orders or TradeCopier integration support.

Recognize strings this decoder cannot interpret

Invalid or unsupported inputs for this exact decoder format

Input or combination	Why it is not decoded
MESZ6 with no context	The full year remains unresolved.
MESZ26 with context 2027	The supplied full year does not match the suffix.
MESZ26 with root ES	The symbol does not start with the declared exact root.
MESA26 with root MES	A is not a recognized month code.
MESZ026 with root MES	Three-digit year suffixes are not accepted.
CME:MESZ26 or MES Z26	Exchange prefixes and internal spaces are outside the format.
ES1! or MESZ26-MESH27	A continuous-chart label or multi-leg spread expression is not one root-month-year string.

A rejection does not establish that a vendor's original instrument is invalid. It means that string is outside this teaching tool's contract. Do not silently remove punctuation from a spread or continuous label and assume the remainder identifies the same instrument. Consult the vendor's description and resolve each actual contract separately.

The named month is not an expiry formula

CME's Three-Month SOFR documentation gives a useful counterexample. Its named month identifies the start of the three-month reference period; the contract reaches final settlement after that period. In CME's September 2026 example, SR3U6 names the September contract even though the reference period continues into December. This explains why the decoder labels its output as the named month, not the expiry month. Reading the letter correctly therefore does not by itself identify the month in which trading ends.

Use the product calendar for last trade, notice and settlement dates. CME's calendar field definitions distinguish these events. The CME expiration calendar provides filters for products and different trading events. Check the exact contract and current broker deadline separately; this decoder retrieves neither. The companion notice and last-trade reference turns them into an operational worksheet.

Prevent a rollover mismatch

Suppose a source moves from its September contract to December while a destination still points at September. Both symbols can share the same market root, but they represent different prices, expiration rules and positions. Selling December does not simply close a September long; it can create a calendar spread.

A continuous chart adds another layer because it may splice several contracts and adjust historical prices. Do not use its label as proof of a current orderable instrument. Before a roll, reconcile open positions, pending orders and destination mappings using full identifiers. After the roll, verify actual fills and residual positions rather than inferring success from the chart's new month label.

For archived orders, preserve the original symbol string alongside its resolved fields. That makes later reconciliation possible if a vendor changes its naming format, or if the same abbreviated year is encountered in a dataset spanning multiple decades.

Keep a reproducible decoding record

Store the untouched original symbol, its vendor or broker namespace, your declared root, month letter, full resolved year and the evidence used to choose that year. Keep the result separate from the exchange calendar and broker instrument identifier. A later reviewer should be able to distinguish a format match from a verified listing and from an order accepted on a particular account.

If an archive supplies only an abbreviated year without reliable context, mark that record unresolved. Guessing a plausible decade may make the data look complete while joining unrelated contracts. Leave the unknown visible until a dated source or original instrument record resolves it.