---
title: Unallocated Costs
canonical: "https://cloudmonitor.ai/docs/using-cloudmonitor/reports/unallocated-costs/"
description: "Spend that belongs to no cost group, how big the gap is, and whether it is getting better or worse."
---

Unallocated cost is spend no allocation rule matched — so it belongs to no cost group, and in
practice to nobody. This report tells you how much of that you have and whether the number is moving
in the right direction.

It's the health check on everything else. Chargeback, budgets and team-level reporting are all only
as good as the fraction of spend that's actually attributed.

## The four numbers

**Total period cost** — the whole bill, allocated and unallocated together. The denominator.

**Period unallocated** — spend in the period that matched no cost group, split into
**Unallocated usage** and **Unallocated reservations**.

**Period unallocated %** — the one to watch. It's a ratio, so it's directly comparable with the
previous period regardless of whether the bill grew, and it doesn't shift when you change cost basis.

**Last month unallocated** — the most recent complete calendar month, shown against that month's
whole bill.

**Unallocated cost over time** charts it, split by usage and commitment purchases.

## Usage and reservations are different problems

Worth separating before you go fixing anything.

**Unallocated usage** is normally a tagging gap. Resources are running without whatever your rules
match on. The fix is upstream, in how resources get created.

**Unallocated reservations** is normally an allocation-rule gap. A commitment purchase is a real
charge that has to land somewhere, and it often doesn't carry the tags an ordinary resource does.
Rules can route these by name — see the cost group code in
[the glossary](/docs/reference/glossary/).

## Why the cost group filter is grayed out

Because it would be a contradiction. Unallocated cost is, by definition, spend outside every cost
group, so scoping it to one group would return nothing. CloudMonitor grays the chip and says so
rather than showing you an empty report.

Every other filter applies normally.

## What to do about it

There's no single right number, but the trend matters more than the level. A percentage that's
climbing means new spend is arriving unattributed faster than you're closing the gap.

Two levers:

- **Allocation rules** route existing spend to a group without touching any resource. Fastest fix,
  and the right one for commitment purchases and shared services.
- **Tagging** fixes it at source, so new resources arrive attributed. Slower, but it's the one that
  stops the problem recurring.

Both are admin work — see the [how-to articles](/docs/how-to/).

## Everyone can see this

Every user is automatically a member of the built-in Unallocated group, so this report is visible to
everyone regardless of which cost groups they belong to. That's deliberate: unattributed spend is
everyone's problem, and hiding it from most of the organization is how it grows.