Abstract Michelle Egan and Jacques Pelkmans provide an overview of the TBT chapter in TTIP and the various  issues  between  the  US  and  the  EU  in  this  area,  which  in  turn  requires  extensive expositions  of  domestic  regulation  in  the  US  and  the  EU.  TBTs,  outside  heavily  regulated sectors such as chemicals, automobiles or medicines (which have separate chapters in TTIP), can  be  caused  by  divergent  (voluntary)  standards,  technical  regulations  and  conformity assessment.  Indeed,  in  all  three  the  US  and  the  EU  have  long  experienced  frictions  with considerable  trading  costs.  The  1998  Mutual  Recognition  Agreement  about  conformity assessment  only  succeeded in  two  out  of  six  sectors.  The  US  and  European  standardisation traditions  differ  and  this  paper  explains  why  it  is  so  hard,  also  economically,  to  realise convergence.  However,  the  authors  reject  the  unproductive  ‘stand-off’  between  US  and  EU negotiators on standardisation and suggest to clarify the enormous economic ‘installed base’ of  prominent  US  standards  in  the  world  economy  and  build  a  solution  from  there.  As  to technical regulation, the prospect of converging regulation (via harmonisation) is often dim, but equivalence (given similar levels of regulatory protection) can be an option.