After completing all 13 atpl exams you have 3 years from the date of last exam passed to gain your cpl(h),if you want to gain an IR this also has to be done within this time period otherwise if you currently hold a cpl(h) and have not completed IR within this time period you are required to resit 7 of the throey exams again.If you posses a cpl(h) and an IR there is no time limit on gaining an ATPL(H) as long as your IR is current you are deemed to have ATPL knowledge and once you have met the requirements ie:multicrew time etc you can apply for your ATPL without having to pass any other theory exams.
Hope that clears up some misconceptions.
