Sure Signal relies on your broadband, so a broadband speed or lower available bandwidth can impact call quality. You’ll need an upload and download speed of at least 1Mbps to use Sure Signal.
Using the internet on multiple devices at the same time can also have an effect, especially if you have a low download or upload speed. You could try switching some of them off to increase speeds, or using the Speed Checker in the My Vodafone app to make sure your connection meets the minimum requirements.
If your connection doesn’t meet the minimum requirements, you’ll need to get in touch with your internet provider. If we’re your internet provider, please get in touch