diff --git a/src/app/api/slack/interactive/route.ts b/src/app/api/slack/interactive/route.ts
index 08f0689..2286bbe 100644
--- a/src/app/api/slack/interactive/route.ts
+++ b/src/app/api/slack/interactive/route.ts
@@ -234,6 +234,16 @@ async function buildDetailsModal(transactionId: number, participantId: number) {
     `SELECT merchant_normalized AS merchant, line_items
        FROM expense_metadata
       WHERE transaction_id = $1 OR matched_transaction_id = $1
+-- Ordered the same way as replaceLineItems (line-items.ts) and
+      -- matchTransaction (intake-router.ts), so every reader of this row
+      -- resolves the same one a write lands on. NULLS LAST because DESC is
+      -- NULLS FIRST and the row that merely POINTS at the transaction has a
+      -- NULL transaction_id.
+      -- Measured 2026-08-21: 667 expense_metadata rows, 147 of them
+      -- pointing-only, and ZERO transactions resolving to more than one row by
+      -- either link — so this changes nothing today. It is here so the readers
+      -- still agree on the day multiplicity appears.
+      ORDER BY (transaction_id = $1) DESC NULLS LAST, id
       LIMIT 1`,
     [transactionId]
   );
diff --git a/src/lib/order-reviews.ts b/src/lib/order-reviews.ts
index 05d434e..46739e7 100644
--- a/src/lib/order-reviews.ts
+++ b/src/lib/order-reviews.ts
@@ -119,6 +119,16 @@ export async function merchantForTransaction(
   const row = await queryRow<{ merchant_normalized: string | null }>(
     `SELECT merchant_normalized FROM expense_metadata
       WHERE transaction_id = $1 OR matched_transaction_id = $1
+-- Ordered the same way as replaceLineItems (line-items.ts) and
+      -- matchTransaction (intake-router.ts), so every reader of this row
+      -- resolves the same one a write lands on. NULLS LAST because DESC is
+      -- NULLS FIRST and the row that merely POINTS at the transaction has a
+      -- NULL transaction_id.
+      -- Measured 2026-08-21: 667 expense_metadata rows, 147 of them
+      -- pointing-only, and ZERO transactions resolving to more than one row by
+      -- either link — so this changes nothing today. It is here so the readers
+      -- still agree on the day multiplicity appears.
+      ORDER BY (transaction_id = $1) DESC NULLS LAST, id
       LIMIT 1`,
     [transactionId]
   );
diff --git a/src/lib/queries.ts b/src/lib/queries.ts
index 6fffce4..b18b0c2 100644
--- a/src/lib/queries.ts
+++ b/src/lib/queries.ts
@@ -367,6 +367,16 @@ export async function getTransactions(ownerId: number, filters: TransactionFilte
       SELECT em.route, em.platform
         FROM expense_metadata em
        WHERE em.transaction_id = t.id OR em.matched_transaction_id = t.id
+       -- Ordered the same way as replaceLineItems (line-items.ts) and
+       -- matchTransaction (intake-router.ts), so every reader of this row
+       -- resolves the same one a write lands on. NULLS LAST because DESC is
+       -- NULLS FIRST and the row that merely POINTS at the transaction has a
+       -- NULL transaction_id.
+       -- Measured 2026-08-21: 667 expense_metadata rows, 147 of them
+       -- pointing-only, and ZERO transactions resolving to more than one row by
+       -- either link — so this changes nothing today. It is here so the readers
+       -- still agree on the day multiplicity appears.
+       ORDER BY (em.transaction_id = t.id) DESC NULLS LAST, em.id
        LIMIT 1
     ) order_ctx ON true
     LEFT JOIN LATERAL (