Honestly, I'm not sure as I think it may depend on your area. If I were you, I would call the real estate agent you worked with to buy the house. They should know all the in's and out's of this and what you will need to do. I would highly recommend calling them and getting their opinion on your situation! http://www.avdr.ca/vinyl-decking
There are a few glitches that come up just as you are getting ready to close on a deal. In the 15 years in this business I have had the biggest problem with decks not being built to code. This includes undersized footings, insufficient support beams as well as homeowners expanding an existing deck without a permit or certificate fo compliance. It becomes very costly to remove, replace and/or retrofit the existing deck to bring it up to code. If you know that your deck is not in compliance, you are better off taking care of it ahead of time by calling your local architect, letting him know that you are in contract and are waiting to close on your home and bring the deck into compliance sooner than later. It can cause problems for you if you are entering into another deal to purchase your new home.
It is my understanding that all decks that were not part of the original building plan and acknowledged under the original CO need a separate CO, i.e. decks added a a later time. Check with your local building department for their regulations. If you are planning on selling and know that you are missing a CO, get it done asap. It will come up in a codes and violations search.