Key strategies

For Excel → board syncs, the key is how a spreadsheet row and a board item stay matched across runs. Pick the strategy when you create the mapping.

App-managed key (default)

The app maintains a monday_id column in your Excel table (adding it if missing). When a row creates a new item, the item's id is written back into that cell; from then on the row and item are matched by id.

• Best for: most imports — nothing to think about, exact matching, renames on either side don't break anything.
• Leave monday_id cells alone. Clearing one makes the row create a fresh item on the next sync.
• If an item is deleted on the board while its row still exists: under source wins the row recreates it; under skip & flag the row is flagged so you decide.

Natural key

You pick one of your mapped columns (say, Order # or Email) as the key. Rows match board items whose key column has the same value.

• Best for: sheets that already have a unique id, or when other systems also write to the board and monday_id bookkeeping isn't possible.
• The key column is yours — the app never writes into it.
• Key values must be unique. Duplicate keys (in the sheet or on the board) are never guessed at: duplicated sheet rows are skipped and flagged; duplicated board items match the first one consistently.
• Rows with an empty key are flagged, not imported.

Which one?