diff --git a/odoo/addons/base/models/res_partner.py b/odoo/addons/base/models/res_partner.py
index ae8ac4e302e..4e62de90ee3 100644
--- a/odoo/addons/base/models/res_partner.py
+++ b/odoo/addons/base/models/res_partner.py
@@ -374,7 +374,9 @@ class Partner(models.Model):
                 domain += [('company_id', 'in', [False, partner.company_id.id])]
             if partner_id:
                 domain += [('id', '!=', partner_id), '!', ('id', 'child_of', partner_id)]
-            partner.same_vat_partner_id = bool(partner.vat) and not partner.parent_id and Partner.search(domain, limit=1)
+            # For VAT number being only one character, we will skip the check just like the regular check_vat
+            should_check_vat = partner.vat and len(partner.vat) != 1
+            partner.same_vat_partner_id = should_check_vat and not partner.parent_id and Partner.search(domain, limit=1)
             # check company_registry
             domain = [
                 ('company_registry', '=', partner.company_registry),