6. For the period beginning on 10th December 2012 and ending on the date on which the new calculation rules come into force for all purposes—
(a)regulation 34(2) of the 2012 Regulations (the general rule for determining gross weekly income) shall be read as if after paragraph (b) there were inserted—
“or
(c)HMRC is unable, for whatever reason, to provide the required information.”;
(b)regulation 69(5) of the 2012 Regulations (non-resident parent with unearned income) shall be read as if after paragraph (b) there were inserted—
“or
(c) HMRC is unable, for whatever reason, to provide the information,”.