You must use customer factory and updateDate to update the custom value $customer = $this->customerFactory->create(); $customerData = $this->customer->getDataModel(); $customerData->setCustomAttribute('cuser_id', 'testnew1235'); $customer->updateData($customerData); $customer->setData('email',"abcd123t@gmail.com"); $customer->setFirstname("First Nametestdfdf"); $customer->setLastname("Last namesdfadsf"); $customer->setPassword("test1123"); $customer->save();