Currently, we cannot place limits on the number of contacts that you sync from your phone or email, however, we do have a 5,000 contact limit on .csv files and spreadsheets.
On average, we have seen that agents who upload 5,000 or less contacts have had the most success on the First app. Uploading a small segment of contacts allows you to really focus on your sphere of influence to help you win more listings and stay in flow with those contacts. Having too many contacts in your First app can dilute your experience and not allow you to see the true value of First.