Whether you need to drill depends on the type of sink you choose. Take for instance drop-in sinks, which come with holes that have already been drilled and cut. (Note that drop-in sinks and faucets purchased separately must have the same number of holes — a 4-hole faucet needs a 4-hole sink, and so on.) Undermount or dual-mount sinks, meanwhile, don’t have pre-drilled holes because they’re typically held in place by brackets on the underside of the countertop. Then there are farmhouse sinks that slide into place and are usually secured by side screws. No matter what type of sink you pick, always refer to your owner’s manual for specific installation instructions.