You can be restricted from submissions, meaning you won't be able to submit reports to certain programs. There are 2 reasons as to why you might be restricted from submissions:
You're a new user and have submitted a large amount of reports in the same day
You run into a program with Signal Requirements that you don't meet
Signal requirements allow programs to specify a required minimum signal that hackers must meet in order to submit reports to that program. Your signal for signal requirements is based on your activity from the last 365 days. If your signal is above their requirement, then you won’t be restricted from submissions for that program. If you don’t meet the required signal for a program, you'll be given a number of trial reports that you can submit so you can still participate in their program.
How do trial reports work?
Trial reports are given when you don't meet the signal requirements for a program. They are given within a 30-day rolling window, and there are limits to the number of trial reports you can submit. These are the limits:
Type of Limit
New Hackers (you have less than 5 resolved reports on HackerOne)
Seasoned Hackers (you have more than 5 resolved reports on HackerOne)
The number of trial reports you're able to submit to a single program
The total number of trial reports you're able to submit on the HackerOne platform
When you have 5 total trial reports left, you'll see a yellow warning box on top of the report submission form letting you know that the number of trial reports you have left is getting lower.
Use your trial reports wisely! These limited chances are the perfect opportunity to submit the best reports you have so that your signal can improve.