If the deceased had an account number for the Quebec sales tax (QST), you will need to obtain, before being able to proceed with the succession/estate inventory of the deceased's property, all the relevant information from Revenu Québec with respect to such tax account.
This letter can also be used in the case where the deceased received a refund check issued by government authorities and that it could not be cashed before the death of the beneficiary.
The information request letter, available on this website, will be suitable for most situations.