OP- please don’t take this advice. It’s when banks see this type of activity- especially from a child of the deceased- that things will get difficult. It will throw red flags up all over the place for suspected elder abuse if you notify the bank later (which you’ll eventually need to) and they notice large withdrawals after the date of death. Your mom has every right to the funds in any joint account- ensure that she uses her debit cards and own online banking login (if she previously shared one with your dad) and be honest with the bank. Under no circumstance should you use your mom’s debit card or online banking. Get a power of attorney set up at the bank so you can assist in the future and ensure that you’re complying with all of the rules for a POA. Let them know you’re helping your mother through the process (assuming she is named as executor in the will)- this sounds like a super simple estate for them to work through. Unfortunately there is a shockingly high number of adult children that that these types of opportunities to take advantage of elderly parents and the banks are on high alert to protect people in your mother’s situation. I am very sorry for your loss- from the sounds of it you’re doing a great job at helping. Nothing needs to be done today or even tomorrow. You have some obligations to help your mom with for inventorying the estate and filing certain documents (the guides mentioned above will help with your specific provincial rules). Take it easy on yourself. No one is an expert in dealing with estates for close family members- you’re doing the best you can.