I’m not sure how death is handled in your part of the world, but I can tell you how we approach things like this in the Southern United States. It’s ok to dress casual to the funeral home here. People that don’t plan to go to the funeral will sometimes put on their Sunday best; when they go to the funeral home. If you’re planning to go to the funeral; then a casual dress like blue jeans and a t-shirt is fine for visitation at the funeral home. Dressing casual to visit gives you a chance to dress nice for the actual funeral day and show your respects then. I do attend many funerals where people show up in casual clothes and I think this is fine. Your presence is more important than what you’re wearing, so never let your dress clothes keep you from attending a family or friend’s funeral. You don’t need to wear a tuxedo shirt to the funeral, but its great if you do. If you don’t plan to put on your Sunday best or don’t have them to put on, still go to the funeral to pay your respects. Just try to dig out the blue jeans you have with the least holes in them and the ones that are least faded. The nicest shirt you have in the closet will work with the jeans and any footwear is fine. It is best to go to the actual funeral in dress clothes, but no one should ever be prevented from attending, because they didn’t throw on a pair of slacks with a dress shirt. I hope this helps when you have to go to the funeral home for visitation or to your next funeral.