Please ensure that
- The wallet is in format of a QR code. If you use a service to convert a text address into a QR code (such as this one), you can check that the QR code address is correct by converting it back to text using your mobile wallet, or a QR code reader on your phone, or this tool or this one
- The brightness on your phone screen is set to maximum
- The address is in “SegWit Compatible (P2SH)” format. These addresses start with a 3. If your app doesn’t support this format, you can use another wallet, such as Electrum, as shown below.
As a reminder, we always recommend using a personal wallet (e.g. Mycelium or BTC.com). Other wallets can be used to buy cryptocurrency, but using exchange wallets to sell can cause delays or cancelled transactions.