SEDOL checksum checker

Client

Reference-data spreadsheets and trade-support tickets often paste SEDOL symbols beside ISIN or CUSIP columns. This page strips separators, confirms the seven-character layout, and recomputes the published mod‑10 check with LSE weights 1, 3, 1, 7, 3, 9—pair it with ISIN validate when the same instrument also carries a twelve-character ISO wrapper.

What this checks

A SEDOL is seven alphanumeric characters: six body symbols plus a mod‑10 check digit using LSE weights 1, 3, 1, 7, 3, 9 on a 0–35 character map (digits stay, A=10 through Z=35). The tool confirms layout and recomputes the seventh digit—it does not prove listing status.

How to use

Paste the full symbol (separators are stripped). Use "Load example" or prefill with ?q= / ?qb= for automation. When the same line also has an ISO wrapper, open ISIN validate for the twelve-character chain.

For North American nine-character symbols, compare CUSIP checker—doubling rules differ from SEDOL weights.

Privacy: checksum math runs locally in your tab. Toolcore does not query LSEG, exchange registries, or market data—format and check digit only.
?

After cleanup the identifier is 7 characters: six body symbols plus one decimal check. Letters map to values 10–35 (A=10 … Z=35). Weights on the body are 1, 3, 1, 7, 3, 9— different from North American CUSIP doubling.

Result

UK and Irish listings often pair SEDOL with a twelve-character ISIN—open ISIN validate when you need country prefix and Luhn expansion. North American desks may use CUSIP checksum instead.

Passes SEDOL mod‑10 check for B0YBKJ7.

Body (6)
B0YBKJ
Check digit
7

Nearby workflows on Toolcore

  • ISIN validate — when spreadsheets carry both UK SEDOL and ISO 6166 ISIN columns for the same line.
  • CUSIP checker — for North American nine-character bodies that sit beside SEDOL in cross-market files.
  • GTIN check — when retail supply-chain GTINs appear in the same onboarding pack as capital-markets ids.

Common use cases

  • Sanity-check a SEDOL copied from a London listing file before loading it into an internal security master.
  • Explain why a seven-character UK symbol fails checksum while the related ISIN still passes ISO Luhn expansion.
  • Spot typos in the six-character body during onboarding when only the SEDOL column is available in legacy CSV feeds.
  • Contrast SEDOL weights (1, 3, 1, 7, 3, 9) with North American CUSIP doubling when desks mix UK and US identifiers.

Common mistakes to avoid

  • Treating a passing check as proof of listing or eligibility

    Checksum validation confirms arithmetic only—not trading status, corporate actions, or regulatory approvals.

  • Applying CUSIP doubling to SEDOL bodies

    SEDOL multiplies each body character by 1, 3, 1, 7, 3, 9 respectively; CUSIP doubles even positions on single-digit values before a different mod‑10 finish.

  • Expecting LSEG master-file metadata

    Issuer names, listing venue, and instrument type require licensed vendor feeds—this page performs local format math only.

FAQ

Does Toolcore query LSEG or the exchange?

No—the check digit and layout rules run entirely in your browser tab.

How does the check digit work?

Map each of the first six characters to 0–35 (digits stay, A=10 through Z=35). Multiply by weights 1, 3, 1, 7, 3, 9, sum the products, then take (10 − sum mod 10) mod 10 as the seventh character.

What about pre-2004 numeric-only SEDOLs?

Modern SEDOLs are seven alphanumeric characters with the same published weight chain; legacy six-digit codes without a letter body are outside this checker’s scope.

Common search terms

Phrases people search for that match this tool. See the full long-tail keyword index.

  • sedol checker online check digit
  • validate sedol checksum in browser
  • london stock exchange sedol mod 10
  • sedol validate no lseg lookup

More tools

Related utilities you can open in another tab—mostly client-side.