What are the problems that I have to think off before permitting for negative range to allot ids to organizations during my application ?

Any disadvantages of storing negative id range once the positive range can be used up during my application ?

One problem with this which i found was should you ever have to wander into performance territory.

Among the systems I needed to focus on needed to perform a Large amount of map lookups according to ID. The maps it had been searching at had > 400 million records, and there have been multiple maps. A roadmap according to an Integer key was where I began. However, for memory efficiency AND speed I wound up switching to an assortment, in which the index was the important thing. Dealing with negative amounts would hinder this.

Another restrictions could be in any kind of BitSet work should you needed to inflict Set mathematics around the IDs.

That being stated, this can be a fairly narrow use situation.

Have you got any code that appears such as this:

int id = FindRecord();

if ( id > 0 )
{
    Success();
}
else
{
    Failure();
}

If that's the case, you will need to refactor it.