• New York's Excelsior Pass lets you find and store your proof of vaccination right on your phone with a QR code, sort of like a boarding pass for an airplane.
• Here's how to set up and use New York's Excelsior Pass.

New York City is set to require proof of Covid-19 vaccination for a range of indoor activities beginning Aug. 16, with full enforcement beginning Sept. 13, which means residents and visitors are going to need to carry their proof of vaccination most of the time.

I'm always worried I'll lose my physical card, so I've found the city's Excelsior Pass on my phone to be helpful. The Excelsior Pass is an app that was first introduced in March 2021 for New York State. It lets you find and store your proof of vaccination right on your phone with a QR code, sort of like a digital boarding pass for an airplane.

The app will only work if you've been vaccinated in New York because it confirms your vaccination against city or state records. If you've been vaccinated elsewhere, you can also download the new NYC Covid Safe app, which simply stores a picture of your card and doesn't match it against records. But I prefer using Excelsior pass since I've gotten used to it over the past few months.

I'll take you through how to set up the Excelsior Pass below. It's a good example of what other cities or states might use if similar vaccine mandates are put in place.

How to set up New York's Excelsior Pass

• Download the NYS Wallet app for iPhone or Android.
• Open the app and enter your name, zip code, phone number, date of birth, what vaccination you received and when you received your second vaccination dose. If you received the single Johnson & Johnson dose, you'll just enter the date you received it.

The information processes and then your card pops up. It looks like this:

That's it. Now your information is stored and ready to use.

How to use New York's Excelsior Pass

When you're ready to use the pass, like at a gym or before entering a restaurant, do this:

• Open the NYS Wallet app that you downloaded.
• Click on the active pass, which is just the card that shows up in the app.
• You'll see a QR code that someone verifying your vaccination can scan.
• You can also add the card to Apple Wallet on iPhone by tapping the "Add to Apple Wallet" button. With this, you can just open the Wallet app on your iPhone to get the QR code.

It works well. I've used it to go to the gym, for example. When I walk in, an employee asks me to confirm my vaccination. I just open the app, tap my pass, they see or scan the QR code, and I'm all set.

Subscribe to CNBC on YouTube.