Lastly, when we are going to transfer WhatsApp contacts and once we have the new phone, we just need to enter the SIM to be able to receive the line verification code.
Then we will download from the Play Store (on the Android) or from the Apple Store (on the iPhone) the WhatsApp application. The steps now are:
Install the WhatsApp application.
Enter your PHONE NUMBER.
We enter the VERIFICATION CODE received by SMS.
We accept when it tells us to RESTORE OUR MESSAGES AND FILE.
In a few seconds or minutes, depending on how many chats you need to restore, we will have our WhatsApp account as we left it on the previous device ready to be used.
These steps are common for Android and iOS devices.