There are two ways to remove people from a flow:
Default: when the flow ends for them.
Forcefully: using the End Flow step.
Every flow has a start (a Trigger step) and an end (an Action step). Regardless of whether you use the End Flow step, every person will eventually leave a flow once they go through all of the steps in the flow.
People will leave the flow below once they receive the last email:
Another way for a person to leave a flow is when they don't satisfy a specific filter criteria.
In the example flow below, people that don't have the Country field America, will leave the flow on the Check Field step and will not receive the email that follows.
The End Flow action step forcefully removes people from the whole flow.
Let's say you have an onboarding email sequence and you want to stop sending onboarding emails when people upgrade their subscription. To do that you could create a separate sub-flow with trigger Stripe Activated Subscription → End flow.
This flow will look like this:
On each last step of the flow you can see how many people completed the flow under the metric "Were here". In the example below 59 people left that flow after the Send Email step:
Let's say you create a flow, 59 people enter and leave that flow, but later you decide to edit the flow and add a few more steps at the end of it.
Once a person leaves the flow, they will not continue to new steps that are added in subsequent edits.
Let's take our previous example, if we add 2 more steps after the last step, the 59 people that were previously on the last step will NOT continue to the newly added Wait step.
However, any new people that enter the flow for the first time and any people that are currently in the flow (i.e. haven't reached the last step, yet) will continue to the newly added steps.
If for some reason you want to stop people from leaving a flow, you could do that by adding a Wait step at the end of the flow. Make sure you give that step a long waiting period like 999 days — that way people will stay in the flow for a long, long time.
Unlike other steps, which are processed immediately, a person will remain on a Wait step for the time period specified on the step. Because they haven't left the Flow, you can add new steps later in the Journey and they will be eligible to proceed to them.