When you buy a new printer and set it up either at 123.hp.com or using the HP Smart app and you sign up for a paid plan you are offered a free trial of Instant Ink. However, if you sign up for the 15 page free plan you are not offered the free trial since you are already on a free plan.
The number of free months depends on the offer at the time and the country of enrollment. You must take advantage of this offer within 7 days. There is no special code and the free months are automatically applied to your account. After 7 days, the free trial offer expires.
During the free trial you can print up to 300 pages per month regardless of the plan you pick (50,100,300). If you pick the 500 or 700 page plan your free trial will be for 500 or 700 pages depending on the plan you chose.
To confirm that you received your free months, check the message on the Confirmation page just before you enroll, or sign into your account page at Instantink.com and find the free months under My Account > My Plan. Free trial months are not offered when you sign up at Instantink.com – only at 123.hp.com and the HP Smart app. Remember to take advantage of the free trial offer while you are setting up your printer!