Making a budget restrictive allows for a better control of worked hours and expenses (billable or not) linked to a project since a restrictive budget is a budget that cannot be exceeded. In other words, when a restrictive budget is reached, no additional time or cost entries can be recorded.

A budget can be set as restrictive no matter its scope (global, per member or per task).

Making a budget restrictive based on worked hours
Let's take the example of a budget whose scope would be "per member" with a "worked hours" budget type. To learn more about how to set a budget, click here.

Let's say a member of your organization has a predefined budget of 10 hours...

...and that member tries to record a time entry exceeding 10 hours (or the total of worked hours exceeds 10 hours), the system will prevent him from doing so:

Making a budget restrictive with a fixed-fee project
Let's take the example of a flat-rate project set at $5000 and for which you wish to generate a profit margin of $1000. You would have to set the budget scope to global, select a budget type based on the costs  (hours worked x hourly rate + expenses), and allocate a budget amount of $4000.

As for the invoice method, you would need to choose the "Project fixed-fee" option and enter the flat-rate amount, in this case $5000.

Any new time or expense entry, billable or not, that would exceed the $5000 fixed-fee would therefore be blocked.

Making a budget restrictive with an hourly rate project
The same logic applies to billable projects based on project hourly rates as described above, except that the project hourly rate will override any member or task predefined rates and will be used to make a budget restrictive.