I believe it is expedient to educate people on how this process works so that they can be well-informed and make better decisions, rather than being tossed to and fro.
When you grant permission to loan apps to access your contacts, a background service is initiated in your Android Kernel the moment you open their apps and perform tasks such as filling out your KYC (Know Your Customer) and applying for a loan. Typically, it takes between 2 to 10 minutes to harvest your contacts and send them to their server. They can code this process in two ways: either sending all contacts at once or one by one.