text: from lib.pyeric.config import get_settings
  from erica.domain.ElsterXml.bufa_numbers import VALID_BUFA_NUMBERS, VALID_TEST_BUFA_NUMBERS
  
  
  def is_valid_bufa(bufa, use_testmerker=False):
      """
      Checks whether a number is a valid bufa. For this it has to be checked against all
      the different tax offices in different states
  
      :param bufa: The first four digits of the electronic tax number; representing the Bundesfinanzamt number
      :param use_testmerker: Allows test_bufas even if the settings do not accept test bufas. Use this for special idnrs.
      """
      if get_settings().accept_test_bufa or use_testmerker:
          return bufa in VALID_BUFA_NUMBERS or bufa in VALID_TEST_BUFA_NUMBERS
  
      return bufa in VALID_BUFA_NUMBERS
  