Congrats John.
HM sends a card on the 60th, 65th, 70th and every year thereafter.
You fill in the form on Buck House's website and send a copy of your marriage certificate and they do the rest. Once you have done it once, you just resubmit the form (without certificate) for following anniversaries.
I did it for my grandparents's 60th and for their 65th. And no doubt for their 70th in 3 and a bit years time.....