Google is now charging for using its mapping services, but it gives you a credit to pay for most or all of the quota. If you have a standard website with average traffic then it will probably not use enough resources to actually get billed. However, Google wants your billing information just in case you go over your quota.
Every month Google will give you a free $200 credit, once you have gone over that usage you will be billed. In order to see what they charge you can view their pricing page: https://cloud.google.com/maps-platform/pricing
Google Maps API Billing Setup Steps
Total Time
Cost
In order to add a new billing account please follow these steps:
Tools
Supplies
Create Your Billing and API
1. Sign into your Google account or create a new one
If you have an account, sign in here
If you don’t have a Google account, you will need to create one.
2. Getting Started with Maps Setup
Once you are logged in to your Google account, navigate to the Google Maps Platform here: https://cloud.google.com/maps-platform/ and click the Get Started button.
3. Create a billing account
If you do not have a billing account associated with your Google account, you will need to create one by clicking “Create Billing Account”.

4. Select Your Country and Continue
Using the dropdown selector, select your country.

5. Enter Your Billing Info:
Add your information then select Start My Free Trial.

6. Automate Billing:
You won’t be billed until you set up automatic billing. However, if you don’t enable (or activate) automatic billing and you run over your free quota your map will stop working until the bill is paid.

7. Enable Google Maps Platform
In the next step you tell Google what services you want to use. Select Maps and Places. If you are using driving directions then also click Routes. Click “Next”.

8. Random Questions
You can skip the next few questions if you don’t want to answer them, they aren’t mandatory.

9. Enable APIs
When you get to the Enable your APIs popup click Enable.

10. Copy your API key
You will be presented with your API key. Click the double squares on the right to copy it. Paste it into a document and save it somewhere that you can get to it later.

11. Retrieve Your Key Later on Google
If you ever lose your key you can return to your Google Cloud Platform console and view your credentials here: https://console.cloud.google.com/apis/credentials

12. What to Do with Your Key
Each website that has a map extension the relies on a key to work will need to have that key replaced with the new key that you have generated. If you notice that your map no longer works on your website it means that the old key needs to be replaced. You will need to send the new key to us so that we can replace the old key with the new one.