Per Google,
"Beginning on June 11, 2018, you’ll need to enable billing with a credit card and have a valid API key for all projects. This will give you the ability to scale easily with less downtime and fewer performance issues. In addition, we’re simplifying our 18 individual APIs into three products: Maps, Routes, and Places."
However, Google do not say anywhere whether it's a hard stop or not. What if I don't enable billing account and do not add credit card information. Will I still be able to access Google APIs such as map, directions, geocode after June 11, 2018?
According to the Google Maps Platform technical support, a billing account without any credit card information will be created for each project without billing account. This means that the API calls will still succeed, as long as they fit within the free tier of $200 per month. If your application goes over the 200$ free tier, the billing account will be closed, and API calls will start failing. The only option after that to reopen billing account is entering the credit card information.
来源：https://stackoverflow.com/questions/50482154/is-it-compulsory-to-enable-billing-account-by-june-11-2018-through-credit-card