diff --git a/CHANGELOG.md b/CHANGELOG.md
index c1076ffd8..ab6f9d146 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ and this project adheres to
 ## Unreleased
 
 <!-- write down unreleased development here -->
+* [thirdparty] Extend the thirdparty search to thirdparty children (https://gitlab.com/champs-libres/departement-de-la-vendee/chill/-/issues/448)
 * [person]: AddPersons: allow creation of person or thirdparty only (no users) (https://gitlab.com/champs-libres/departement-de-la-vendee/chill/-/issues/422)
 * [person]: AddPersons: allow creation of person or thirdparty depending on allowed types (https://gitlab.com/champs-libres/departement-de-la-vendee/chill/-/issues/422)
 * [person]: AddPersons: add suggestion of name when creating new person or thirdparty (https://gitlab.com/champs-libres/departement-de-la-vendee/chill/-/issues/422)
diff --git a/src/Bundle/ChillThirdPartyBundle/Search/ThirdPartyApiSearch.php b/src/Bundle/ChillThirdPartyBundle/Search/ThirdPartyApiSearch.php
index 994b9d65c..e4b7f43af 100644
--- a/src/Bundle/ChillThirdPartyBundle/Search/ThirdPartyApiSearch.php
+++ b/src/Bundle/ChillThirdPartyBundle/Search/ThirdPartyApiSearch.php
@@ -87,14 +87,24 @@ class ThirdPartyApiSearch implements SearchApiInterface
         foreach ($strs as $str) {
             if (!empty($str)) {
                 $wheres[] = "(LOWER(UNACCENT(?)) <<% tparty.canonicalized OR
-                    tparty.canonicalized LIKE '%' || LOWER(UNACCENT(?)) || '%')";
-                $whereArgs[] = [$str, $str];
-                $pertinence[] = 'STRICT_WORD_SIMILARITY(LOWER(UNACCENT(?)), tparty.canonicalized) + ' .
-                   "(tparty.canonicalized LIKE '%s' || LOWER(UNACCENT(?)) || '%')::int + " .
+                    tparty.canonicalized LIKE '%' || LOWER(UNACCENT(?)) || '%')
+                    OR
+                    (LOWER(UNACCENT(?)) <<% parent.canonicalized OR
+                    parent.canonicalized LIKE '%' || LOWER(UNACCENT(?)) || '%')
+                    ";
+                $whereArgs[] = [$str, $str, $str, $str];
+                $pertinence[] = 'GREATEST(
+                        STRICT_WORD_SIMILARITY(LOWER(UNACCENT(?)), tparty.canonicalized),
+                        STRICT_WORD_SIMILARITY(LOWER(UNACCENT(?)), parent.canonicalized)
+                    ) + ' .
+                    "GREATEST(
+                        (tparty.canonicalized LIKE '%s' || LOWER(UNACCENT(?)) || '%')::int,
+                        (parent.canonicalized LIKE '%s' || LOWER(UNACCENT(?)) || '%')::int
+                    ) + " .
                    // take postcode label into account, but lower than the canonicalized field
                    "COALESCE((LOWER(UNACCENT(cmpc.label)) LIKE '%' || LOWER(UNACCENT(?)) || '%')::int * 0.3, 0) + " .
                    "COALESCE((LOWER(UNACCENT(cmpc_p.label)) LIKE '%' || LOWER(UNACCENT(?)) || '%')::int * 0.3, 0)";
-                $pertinenceArgs[] = [$str, $str, $str, $str];
+                $pertinenceArgs[] = [$str, $str, $str, $str, $str, $str];
             }
         }