Google is changing the way its Google Local Services ads work, which could affect millions of small businesses.

Google Local Services ads run locally and are a big way that small businesses market their goods and services. Ads appear on the top of Google search results.

Starting November 21, only businesses with a verified Google Business Profile will be able to run the ads.

The change affects businesses in Europe, the Middle East and Africa and “select” businesses in the U.S. and Canada, Google said in an online post. The company didn’t immediately respond to a request for comment.

The change is an effort to crack down on fraud. But legitimate small businesses could be hurt if they're unaware of the change. If a small business' Google Business Profile's name and address doesn't match the information with the ad, advertising will be paused.

Getting verified on Google isn't difficult, but it does take some time. Business owners must add or claim their business address on Google. Then owners will need to verify the address through phone, text, email, or video.

The process varies by business category and location and may include giving information about background, business registration, insurance, and license checks.

Google's verifications can take up to seven business days. Once a business is verified, its owner gets notified.