Absolutely, if you are basting and quilting it yourself, you need a couple of inches on all 4 aides, which when you have finished quilting, you will trim off evenly with the top to prepare to bind it. A LA quilter will probably request at least 4 inches extra on all 4 sides. You should at least ad a strip to the sides that the backing is shorter than the front, as you will not be able to quilt to the edges-you will have to cut off part of the top to bind it. If you are not going to do allot of quilting (say, just quilt in the ditch or a simple block design) it won't be AS critical, but you still need at least a couple of inches of extra backing on all 4 sides. Be careful when layering your sandwich as well, that you get your top and batting CENTERED on the back, so you don't end up getting the whole thing basted, then discovering you had it a bit off-center and have a corner of the top that doesn't have batting or backing under it.