You will be billed on the first of the month for the programs you purchased for the prior month. Your credit card will be automatically charged at the time of billing.
In the case of Yelp Ads, you are charged for each ad-related click until you exhaust your ad budget for the month. For example, if you set a maximum monthly budget of $300/mo., you would be charged at the beginning of the month for each ad-related click you received in the prior month up to a maximum of $300 for the month. Note that you are not charged when someone clicks on your business when it organically appears as a relevant search result (as opposed to a relevant ad).
In the case of our various Page Upgrade products, like Enhanced Profiles, Business Highlights, Verified License and others, you are charged a fixed amount at the beginning of the month for the prior month.
If you have additional questions, use our Advertiser Live Chat option on biz.yelp.com, give us a call at 855-380-9357, or submit a ticket through your Yelp for Business account. If you have a dedicated Customer Success Manager for your account you can find their contact information on the Billing page of Yelp for Business.