Question: Can we take the Threefold Refuge and receive the Five Precepts on behalf of deceased loved ones?
Answer: While going through the above ceremonies, we can think of ourselves as doing so with departed loved ones (or even all beings). However, this does not mean they have also officially taken refuge and received the precepts, as their consciousnesses might not be around to go through the same ceremonies – though there is some possibility.
For taking refuge and receiving precepts, there must be personal commitment. Even if they are around, and merely rejoiced on your commitment, they have still yet to commit personally. Rejoice does create some merits and spiritual affinity to the Triple Gem and the precepts though. Merits can also be dedicated to the deceased, in the hope that they have stronger affinity in future,
It is thus best to take refuge and receive the precepts personally when alive. If immobile due to ageing and sickness, unable to prostrate and chant along during the ceremonies, commitment can be expressed on their behalf as long as they understand, and are willing to commit. They can be there to witness the ceremonies too, or reported of how they proceeded.