Local and global labels have the same name

Diagnostic signature

Local and global labels have the same name

KiCad's Electrical Rules Checker (ERC) warns when a local label and a global label share the exact same text identifier, preventing ambiguous connectivity and unlinked nets across hierarchical schematic sheets.

What it means

This diagnostic indicates that a local label (which establishes connectivity exclusively within a single schematic page) and a global label (which establishes connectivity across all sheets in the project hierarchy) have been assigned the identical text string. In KiCad, net labels are matched by their text values, meaning the schematic editor has detected a naming collision between two differently scoped connection identifiers.

Why it happens

The Electrical Rules Checker (ERC) emits this warning because reusing the identical name for both local and global scopes creates severe ambiguity that frequently results in unintended board connectivity. If the identically named labels reside on separate schematic sheets, KiCad will not electrically link them, which often breaks a designer's assumption that the shared name implies a unified connection. Conversely, if both labels exist on the same sheet, KiCad forces a connection, unintentionally elevating the local net's scope to global. The tool flags this condition to enforce strict semantic separation between local and global signals, preventing silent open circuits or shorts.

Minimal reproduction

Local Label: DATA_BUS
Global Label: DATA_BUS

How to fix it

Resolve the scope ambiguity by either renaming the local label to a distinct identifier or replacing the local label with a global label, depending on the required net connectivity.

```Schematic
Local Label: DATA_BUS_LOCAL
Global Label: DATA_BUS_GLOBAL
```

Step 1

• Double-click the ERC marker in the schematic to locate the conflicting labels.

Step 2

• Determine the intended electrical scope of the affected net (whether it must cross sheet boundaries or remain isolated).

Step 3

• If the net must be accessible across multiple hierarchical sheets, delete the local label and replace it with a global label of the same name.

Step 4

• If the net is intended to remain confined to its current sheet, rename the local label to a distinct, non-conflicting identifier (e.g., 'DATA_BUS_LOCAL').

Step 5

• Re-run the Electrical Rules Checker to ensure the diagnostic is cleared and all nets resolve to their correct scope.

Upstream references

Schematic Editor | 9.0 | English | Documentation - KiCad Docs

Schematic Editor | master | English | Documentation - KiCad Docs