Ans. All the books of account and related documents should be kept at the principal place of business, which means that generally where the business or profession is generally carried on. All the necessary documents shall be preserved for at least six years from the end of relevant Assessment year i.e for a total of seven financial years from the end of the relevant year. When the assessment has been reopened, all the books of account and other documents which were kept and maintained at the time of reopening of assessment should continue to be so kept and maintained till the assessment which has been reopened gets completed.