# Untaggable Cost Tagging

Not all cloud costs can be tagged at the source.

In real-world cloud environments, a significant portion of spend originates from **system-generated, billing-level, or shared infrastructure charges** that do not inherit resource tags.

If left unmanaged, these costs appear as:

* Unallocated
* Uncategorized
* Attributed to "No Owner"
* Dumped into root accounts

This creates reporting gaps and weakens financial accountability.

Virtual Tags solve this.

***

### Why Some Costs Cannot Be Tagged

Certain charges are generated:

* At billing time (not resource level)
* Across accounts
* Outside of compute resources
* At platform or enterprise agreement level

These charges **do not carry native tags**, even if tagging hygiene is strong.

Examples include:

* Data transfer between services
* Enterprise Discount Program (EDP) adjustments
* Support plan fees
* Reserved Instance (RI) amortization
* Savings Plan (SP) amortization
* Cross-account networking
* RDS automated backups
* Out-of-cycle adjustments
* Marketplace subscriptions

***

### How Virtual Tags Solve This

Virtual Tags allow rule-based allocation using billing metadata such as:

* Usage Type
* Charge Type
* Service
* Region
* Account
* Resource Name

Instead of modifying cloud tags, OneLens applies allocation logic during the cost pipeline.

This ensures 100% cost allocation coverage — even for costs that cannot be tagged natively.

***

### Example Rule

If:

* Usage Type contains `"DataTransfer"`
* Region = `us-east-1`

Then:

→ Assign to **Platform Shared Cost Centre**

This ensures shared networking costs are consistently allocated to the correct business owner.

***

### Common Untaggable Cost Examples

Below is a reference table of real-world untaggable or system-level charges and how they are typically handled.

| Cloud | Cost Type                                | Why It’s Untaggable                | Typical Allocation Strategy                           | Example Virtual Tag Rule                                         |
| ----- | ---------------------------------------- | ---------------------------------- | ----------------------------------------------------- | ---------------------------------------------------------------- |
| AWS   | Inter-AZ / Inter-Region Data Transfer    | Generated at network billing layer | Allocate to Platform or proportional to consuming BUs | `Provider = AWS` AND `Usage Type contains "DataTransfer"`        |
| AWS   | NAT Gateway Data Processing              | Network-layer charge               | Proportional split across consuming cost centres      | `Service = AmazonVPC` AND `Usage Type contains "NatGateway"`     |
| AWS   | RDS Automated Backup Storage             | System-generated backup usage      | Assign to owning application team                     | `Service = AmazonRDS` AND `Usage Type contains "BackupUsage"`    |
| AWS   | Enterprise Support Fee                   | % of monthly spend                 | Even split or proportional across all cost centres    | `Charge Type = Support`                                          |
| AWS   | Marketplace Subscription                 | Subscription-level billing         | Assign to owning BU                                   | `Billing Entity = AWS Marketplace`                               |
| AWS   | EDP (Enterprise Discount Program) Credit | Applied post usage                 | Proportional to total spend                           | `Line Item Type = Discount`                                      |
| AWS   | OOC (Out-of-Cycle) Charge                | Manual billing adjustment          | Assign to Finance Shared cost centre                  | `Line Item Type = Fee` AND `Description contains "Out of Cycle"` |

| Cloud | Cost Type                        | Why It’s Untaggable               | Typical Allocation Strategy          | Example Virtual Tag Rule                                     |
| ----- | -------------------------------- | --------------------------------- | ------------------------------------ | ------------------------------------------------------------ |
| Azure | Inter-Region Data Transfer       | Generated at network layer        | Allocate to Platform or proportional | `Provider = Azure` AND `Meter Category contains "Bandwidth"` |
| Azure | Azure Support Plan               | Subscription-level charge         | Even split across BUs                | `Meter Category = Support`                                   |
| Azure | Backup Vault Storage             | Generated by Azure Backup service | Assign to owning BU                  | `Service Name = Azure Backup`                                |
| Azure | Marketplace Charges              | Subscription-level billing        | Map to owning BU                     | `Publisher Type = Marketplace`                               |
| Azure | EA (Enterprise Agreement) Credit | Applied at billing account level  | Proportional across cost centres     | `Charge Type = Credit`                                       |

| Cloud | Cost Type                    | Why It’s Untaggable          | Typical Allocation Strategy | Example Virtual Tag Rule                                         |
| ----- | ---------------------------- | ---------------------------- | --------------------------- | ---------------------------------------------------------------- |
| GCP   | Inter-Region Network Egress  | Network-layer billing        | Proportional allocation     | `Provider = GCP` AND `SKU Description contains "Network Egress"` |
| GCP   | Committed Use Discount (CUD) | Billing-level construct      | Proportional allocation     | `Credit Type contains "CommittedUseDiscount"`                    |
| GCP   | Sustained Use Discount       | Applied post-usage           | Proportional allocation     | `Credit Type contains "SustainedUsage"`                          |
| GCP   | Cloud Support                | Billing account-level charge | Even split                  | `Service Description contains "Support"`                         |
| GCP   | Snapshot Storage             | Generated by system backup   | Assign to owning BU         | `SKU Description contains "Snapshot"`                            |
| GCP   | Marketplace Subscription     | Subscription billing         | Assign to BU                | `Service Description contains "Marketplace"`                     |

| Cloud | Cost Type              | Why It’s Untaggable        | Typical Allocation Strategy | Example Virtual Tag Rule                                     |
| ----- | ---------------------- | -------------------------- | --------------------------- | ------------------------------------------------------------ |
| OCI   | Data Transfer Outbound | Network-layer charge       | Proportional allocation     | `Provider = OCI` AND `Usage Type contains "DataTransferOut"` |
| OCI   | Support Subscription   | Account-level subscription | Even split                  | `Service Name contains "Support"`                            |
| OCI   | Reserved Capacity      | Billing-level allocation   | Proportional allocation     | `Usage Type contains "ReservedCapacity"`                     |
| OCI   | Backup Storage         | System-generated           | Assign to owning BU         | `Service Name contains "Backup"`                             |
| OCI   | Marketplace Listing    | Subscription billing       | Map to BU                   | `Service Category = Marketplace`                             |

## How to Think About These Rules

When creating Virtual Tag rules for untaggable costs:

1. Identify the billing dimension that uniquely describes the cost\
   (Usage Type, Meter Category, SKU Description, Charge Type)
2. Decide allocation strategy:
   * Even split
   * Proportional
   * Fixed percentage
3. Assign to:
   * A Shared Platform cost centre
   * A Finance root cost centre
   * A Specific BU

***

### What Happens Without Virtual Tags

Without rule-based allocation:

* Untagged costs appear under “Unallocated”
* Finance sees reconciliation gaps
* BU-level reports become inaccurate
* Engineering cannot identify optimization scope
* Shared services distort team budgets
* Leadership loses trust in reporting

Over time, this erodes cost accountability.

***

### What Happens With Virtual Tags

With proper Virtual Tag configuration:

* 100% cost allocation coverage
* No orphan spend
* Clean BU-level reporting
* Fair shared cost distribution
* Accurate margin analysis
* Audit-ready cost transparency

Finance trusts the numbers.\
Engineering trusts the attribution.\
Leadership trusts the reporting.

***

### Best Practice

Start by:

1. Identifying top unallocated cost categories.
2. Creating targeted Virtual Tag rules for those categories.
3. Reviewing allocation impact before pipeline execution.
4. Monitoring allocation accuracy monthly.

Untagged cost is not a tagging failure — it is a billing reality.\
Virtual Tags ensure that reality does not break your reporting.