diff --git a/CRM/Contact/Import/Form/DataSource.php b/CRM/Contact/Import/Form/DataSource.php
index b39b67401094..443bf956b896 100644
--- a/CRM/Contact/Import/Form/DataSource.php
+++ b/CRM/Contact/Import/Form/DataSource.php
@@ -176,6 +176,7 @@ public function postProcess() {
       $this->createUserJob();
     }
     else {
+      $this->flushDataSource();
       $this->updateUserJobMetadata('submitted_values', $this->getSubmittedValues());
     }
     // Setup the params array
@@ -199,11 +200,6 @@ public function postProcess() {
 
     CRM_Core_Session::singleton()->set('dateTypes', $storeParams['dateFormats']);
 
-    //hack to prevent multiple tables.
-    $this->_params['import_table_name'] = $this->get('importTableName');
-    if (!$this->_params['import_table_name']) {
-      $this->_params['import_table_name'] = 'civicrm_import_job_' . md5(uniqid(rand(), TRUE));
-    }
     $this->instantiateDataSource();
 
     // We should have the data in the DB now, parse it
diff --git a/CRM/Import/DataSource.php b/CRM/Import/DataSource.php
index 1fce11a312fe..66e80574af57 100644
--- a/CRM/Import/DataSource.php
+++ b/CRM/Import/DataSource.php
@@ -300,4 +300,37 @@ protected function updateUserJobMetadata(string $key, array $data): void {
     $this->userJob['metadata'] = $metaData;
   }
 
+  /**
+   * Purge any datasource related assets when the datasource is dropped.
+   *
+   * This is the datasource's chance to delete any tables etc that it created
+   * which will now not be used.
+   *
+   * @param array $newParams
+   *   If the dataSource is being updated to another variant of the same
+   *   class (eg. the csv upload was set to no column headers and they
+   *   have resubmitted WITH skipColumnHeader (first row is a header) then
+   *   the dataSource is still CSV and the params for the new intance
+   *   are passed in. When changing from csv to SQL (for example) newParams is
+   *   empty.
+   *
+   * @return array
+   *   The details to update the DataSource key in the userJob metadata to.
+   *   Generally and empty array but it the datasource decided (for example)
+   *   that the table it created earlier is still consistent with the new params
+   *   then it might decided not to drop the table and would want to retain
+   *   some metadata.
+   *
+   * @throws \API_Exception
+   * @throws \CRM_Core_Exception
+   */
+  public function purge(array $newParams = []) :array {
+    // The old name is still stored...
+    $oldTableName = $this->getTableName();
+    if ($oldTableName) {
+      CRM_Core_DAO::executeQuery('DROP TABLE IF EXISTS ' . $oldTableName);
+    }
+    return [];
+  }
+
 }
diff --git a/CRM/Import/DataSource/CSV.php b/CRM/Import/DataSource/CSV.php
index a21a4f01f691..43c6120c9483 100644
--- a/CRM/Import/DataSource/CSV.php
+++ b/CRM/Import/DataSource/CSV.php
@@ -93,7 +93,7 @@ public function postProcess(&$params, &$db, &$form) {
     $result = self::_CsvToTable(
       $file,
       $firstRowIsColumnHeader,
-      CRM_Utils_Array::value('import_table_name', $params),
+      NULL,
       CRM_Utils_Array::value('fieldSeparator', $params, ',')
     );
 
diff --git a/CRM/Import/DataSource/SQL.php b/CRM/Import/DataSource/SQL.php
index 3d123ce6a900..1d3e7c8d4ae4 100644
--- a/CRM/Import/DataSource/SQL.php
+++ b/CRM/Import/DataSource/SQL.php
@@ -94,7 +94,7 @@ public static function formRule($fields, $files, $form) {
    */
   public function postProcess(&$params, &$db, &$form) {
     $importJob = new CRM_Contact_Import_ImportJob(
-      CRM_Utils_Array::value('import_table_name', $params),
+      NULL,
       $params['sqlQuery'], TRUE
     );
 
diff --git a/CRM/Import/Forms.php b/CRM/Import/Forms.php
index 938f8f5f6d58..4181a43869c9 100644
--- a/CRM/Import/Forms.php
+++ b/CRM/Import/Forms.php
@@ -235,6 +235,35 @@ protected function buildDataSourceFields(): void {
     }
   }
 
+  /**
+   * Flush datasource on re-submission of the form.
+   *
+   * If the form has been re-submitted the datasource might have changed.
+   * We tell the dataSource class to remove any tables (and potentially files)
+   * created last form submission.
+   *
+   * If the DataSource in use is unchanged (ie still CSV or still SQL)
+   * we also pass in the new variables. In theory it could decide that they
+   * have not actually changed and it doesn't need to do any cleanup.
+   *
+   * In practice the datasource classes blast away as they always have for now
+   * - however, the sql class, for example, might realise the fields it cares
+   * about are unchanged and not flush the table.
+   *
+   * @throws \API_Exception
+   * @throws \CRM_Core_Exception
+   */
+  protected function flushDataSource(): void {
+    // If the form has been resubmitted the datasource might have changed.
+    // We give the datasource a chance to clean up any tables it might have
+    // created. If we are still using the same type of datasource (e.g still
+    // an sql query
+    $oldDataSource = $this->getUserJobSubmittedValues()['dataSource'];
+    $oldDataSourceObject = new $oldDataSource($this->getUserJobID());
+    $newParams = $this->getSubmittedValue('dataSource') === $oldDataSource ? $this->getSubmittedValues() : [];
+    $oldDataSourceObject->purge($newParams);
+  }
+
   /**
    * Get the relevant datasource object.
    *
diff --git a/tests/phpunit/CRM/Contact/Import/Form/DataSourceTest.php b/tests/phpunit/CRM/Contact/Import/Form/DataSourceTest.php
index 2d096185abe9..4c71051c4f25 100644
--- a/tests/phpunit/CRM/Contact/Import/Form/DataSourceTest.php
+++ b/tests/phpunit/CRM/Contact/Import/Form/DataSourceTest.php
@@ -52,7 +52,6 @@ public function testBuildForm(): void {
    *
    * @throws \API_Exception
    * @throws \CRM_Core_Exception
-   * @throws \Civi\API\Exception\UnauthorizedException
    */
   public function testDataSources(): void {
     $this->createLoggedInUser();