In EASA, once you have completed the ATPL TK exams you have three years to finish the flying side. There is (or should be) no dispensation from this but I guess in extenuating circumstances somebody could put up a case for extensions…. Not sure if COVID would count as extenuating circumstances but we will probably see soon. Running out of money or “not had the time” don’t usually work.
if you are on an integrated ATPL this should all be managed by your training provider.
For modular, Any flying completed or qualifications gained up to that point remain valid or creditable unless they fall outside normal “course” lengths (e.g. six months from start to finish…) but would count towards any experience requirements (i.e 200 hours for CPL issue.