diff --git a/web/modules/custom/figli_compta_ledger/figli_compta_ledger.routing.yml b/web/modules/custom/figli_compta_ledger/figli_compta_ledger.routing.yml
index 5b37a50..30de5eb 100644
--- a/web/modules/custom/figli_compta_ledger/figli_compta_ledger.routing.yml
+++ b/web/modules/custom/figli_compta_ledger/figli_compta_ledger.routing.yml
@@ -47,3 +47,10 @@ figli_compta_ledger.api_annees:
     _controller: '\Drupal\figli_compta_ledger\Controller\LedgerStatsController::annees'
   requirements:
     _permission: 'access content'
+
+figli_compta_ledger.api_reconciliation_ouverture:
+  path: '/lignes/api/reconciliation-ouverture'
+  defaults:
+    _controller: '\Drupal\figli_compta_ledger\Controller\LedgerStatsController::reconciliationOuverture'
+  requirements:
+    _permission: 'access content'
diff --git a/web/modules/custom/figli_compta_ledger/js/home.js b/web/modules/custom/figli_compta_ledger/js/home.js
index c869f41..86c1c33 100644
--- a/web/modules/custom/figli_compta_ledger/js/home.js
+++ b/web/modules/custom/figli_compta_ledger/js/home.js
@@ -119,6 +119,16 @@
     return json.annees || [];
   }
 
+  // { "2023": { "Bachir": -0.03, ... }, ... } -- years where the actual
+  // ouverture doesn't match the previous year's calculated closing
+  // balance (that year's own ouverture + every movement dated within
+  // it). Small dataset (a handful of year boundaries), fetched once.
+  async function fetchOuvertureEcarts() {
+    const res = await fetch('/lignes/api/reconciliation-ouverture', { headers: { Accept: 'application/json' } });
+    if (!res.ok) throw new Error('/lignes/api/reconciliation-ouverture a répondu ' + res.status);
+    return res.json();
+  }
+
   async function fetchYearTotals(annee) {
     const res = await fetch('/lignes/api/totaux?annee=' + encodeURIComponent(annee), { headers: { Accept: 'application/json' } });
     if (!res.ok) throw new Error('/lignes/api/totaux a répondu ' + res.status);
@@ -182,6 +192,7 @@
         allComptes: ['Sandrine', 'Maud', 'Ouidade', 'Chloé', 'Bachir', 'Valentin', 'EXT.', 'EXT.WEB'],
         allClientsList: [],
         allYearsList: [],
+        ouvertureEcarts: {},
         filterCompte: '',
         filterClient: '',
         filterType: '',
@@ -316,6 +327,22 @@
       formatEur(v) {
         return v === null || v === undefined ? '' : EUR.format(v);
       },
+      // Écart between this ouverture row's year and the previous year's
+      // calculated closing balance -- restricted to whichever compte(s)
+      // this specific row's répartition actually touches (ouverture lines
+      // are entered one per compte, so showing every compte's écart on
+      // every row would just repeat the same list). Null if this row's
+      // compte(s) reconcile cleanly.
+      ouvertureEcart(item) {
+        if (item.type !== 'ouverture' || !item.date) return null;
+        const annee = item.date.slice(0, 4);
+        const ecarts = this.ouvertureEcarts[annee];
+        if (!ecarts) return null;
+        const relevant = Object.keys(item.parCompte).filter((c) => ecarts[c] !== undefined);
+        if (!relevant.length) return null;
+        const detail = relevant.map((compte) => compte + ' : ' + this.formatEur(ecarts[compte])).join(', ');
+        return { detail, comptes: relevant.length };
+      },
       // jj/mm/aa -- shorter than the API's ISO yyyy-mm-dd, saves column
       // width in a table already packed with 8 compte columns.
       formatDate(iso) {
@@ -638,6 +665,7 @@
       // "whatever happens to be loaded right now".
       fetchClientNames().then((names) => { this.allClientsList = names; }).catch(() => {});
       fetchYearsList().then((years) => { this.allYearsList = years; }).catch(() => {});
+      fetchOuvertureEcarts().then((ecarts) => { this.ouvertureEcarts = ecarts; }).catch(() => {});
       jQuery(document).on('dialog:afterclose', () => this.reloadWindow());
       await this.$nextTick();
       const wrap = this.$refs.tableWrap;
diff --git a/web/modules/custom/figli_compta_ledger/src/Controller/LedgerStatsController.php b/web/modules/custom/figli_compta_ledger/src/Controller/LedgerStatsController.php
index d27060b..2e3a34b 100644
--- a/web/modules/custom/figli_compta_ledger/src/Controller/LedgerStatsController.php
+++ b/web/modules/custom/figli_compta_ledger/src/Controller/LedgerStatsController.php
@@ -96,4 +96,80 @@ class LedgerStatsController extends ControllerBase {
     return new JsonResponse(['annees' => $annees]);
   }
 
+  /**
+   * GET /lignes/api/reconciliation-ouverture -- per compte, checks that
+   * each year's "ouverture" (opening balance) matches the *calculated*
+   * closing balance of the previous year (that year's own ouverture plus
+   * every movement dated within it). The historical spreadsheets carried
+   * real year-to-year gaps that were preserved as-is during migration
+   * (never corrected) -- this surfaces them instead of hiding them, same
+   * principle as the per-ligne écart column.
+   *
+   * Response: { "2023": { "Bachir": -12.34, "EXT.WEB": 5 }, ... } -- only
+   * years with at least one compte off by more than a cent, and never the
+   * very first year on record (nothing to compare it against).
+   */
+  public function reconciliationOuverture() {
+    $connection = \Drupal::database();
+    $query = $connection->select('node__field_date_ligne', 'd');
+    $query->innerJoin('node__field_type_ligne', 't', 't.entity_id = d.entity_id');
+    $query->innerJoin('node__field_repartition', 'r', 'r.entity_id = d.entity_id');
+    $query->innerJoin('paragraph__field_montant', 'm', 'm.entity_id = r.field_repartition_target_id');
+    $query->innerJoin('paragraph__field_compte', 'c', 'c.entity_id = r.field_repartition_target_id');
+    $query->innerJoin('taxonomy_term_field_data', 'tc', 'tc.tid = c.field_compte_target_id');
+    $query->condition('d.bundle', 'ligne_comptable');
+    $query->addExpression('SUBSTRING(d.field_date_ligne_value, 1, 4)', 'annee');
+    $query->addExpression("CASE WHEN t.field_type_ligne_value = 'ouverture' THEN 1 ELSE 0 END", 'is_ouverture');
+    $query->addField('tc', 'name', 'compte');
+    $query->addExpression('SUM(m.field_montant_value)', 'total');
+    $query->groupBy('annee');
+    $query->groupBy('is_ouverture');
+    $query->groupBy('compte');
+    $rows = $query->execute()->fetchAll();
+
+    $ouverture = [];
+    $mouvement = [];
+    foreach ($rows as $row) {
+      if ($row->is_ouverture) {
+        $ouverture[$row->annee][$row->compte] = ($ouverture[$row->annee][$row->compte] ?? 0) + (float) $row->total;
+      }
+      else {
+        $mouvement[$row->annee][$row->compte] = ($mouvement[$row->annee][$row->compte] ?? 0) + (float) $row->total;
+      }
+    }
+
+    $annees = array_unique(array_merge(array_keys($ouverture), array_keys($mouvement)));
+    sort($annees);
+
+    $result = [];
+    foreach ($annees as $i => $annee) {
+      if ($i === 0) {
+        continue;
+      }
+      $precedente = (string) ((int) $annee - 1);
+      if (empty($ouverture[$annee]) || (!isset($ouverture[$precedente]) && !isset($mouvement[$precedente]))) {
+        continue;
+      }
+      $comptes = array_unique(array_merge(
+        array_keys($ouverture[$annee]),
+        array_keys($ouverture[$precedente] ?? []),
+        array_keys($mouvement[$precedente] ?? [])
+      ));
+      $ecarts = [];
+      foreach ($comptes as $compte) {
+        $ouvertureReelle = $ouverture[$annee][$compte] ?? 0;
+        $clotureCalculee = ($ouverture[$precedente][$compte] ?? 0) + ($mouvement[$precedente][$compte] ?? 0);
+        $ecart = round($ouvertureReelle - $clotureCalculee, 2);
+        if (abs($ecart) > 0.01) {
+          $ecarts[$compte] = $ecart;
+        }
+      }
+      if ($ecarts) {
+        $result[$annee] = $ecarts;
+      }
+    }
+
+    return new JsonResponse($result);
+  }
+
 }
diff --git a/web/modules/custom/figli_compta_ledger/templates/figli-compta-home.html.twig b/web/modules/custom/figli_compta_ledger/templates/figli-compta-home.html.twig
index 9e57b25..907637d 100644
--- a/web/modules/custom/figli_compta_ledger/templates/figli-compta-home.html.twig
+++ b/web/modules/custom/figli_compta_ledger/templates/figli-compta-home.html.twig
@@ -123,6 +123,11 @@
                 :title="reconciliationByEntree.get(item.id).detail"
                 @click="toggleEntreeFilter(item.id)"
               >{{ reconciliationByEntree.get(item.id).count }} sortie{{ reconciliationByEntree.get(item.id).count > 1 ? 's' : '' }} liée{{ reconciliationByEntree.get(item.id).count > 1 ? 's' : '' }}<template v-if="reconciliationByEntree.get(item.id).resteAVerser > 0"> · reste {{ formatEur(reconciliationByEntree.get(item.id).resteAVerser) }}</template><template v-if="reconciliationByEntree.get(item.id).surVerse > 0"> · sur-versé {{ formatEur(reconciliationByEntree.get(item.id).surVerse) }}</template></span>
+              <span
+                v-if="item.type === 'ouverture' && ouvertureEcart(item)"
+                class="figli-recon-badge is-anomalie"
+                :title="'Écart avec la clôture calculée de ' + (item.date.slice(0, 4) - 1) + ' : ' + ouvertureEcart(item).detail"
+              >⚠ écart clôture {{ item.date.slice(0, 4) - 1 }} ({{ ouvertureEcart(item).comptes }} compte{{ ouvertureEcart(item).comptes > 1 ? 's' : '' }})</span>
             </td>
             <td class="amount" :class="montantClass(item.montant_ht)">{{ formatEur(item.montant_ht) }}</td>
             <td class="amount">{{ formatEur(item.montant_ttc) }}</td>