Billing Accounts, Budgets and Labels

GCP Basics · Foundations – Regions, Resource Hierarchy, gcloud and Billing · Lesson 4 of 5

Projects are paid through a Cloud Billing account; budgets send alerts (they do not cap spending), labels split costs, and the BigQuery billing export gives you detailed data.

A Cloud Billing account pays for one or more projects. A project without an active billing account cannot use paid services.

flowchart LR
  BA["Cloud Billing account"] --> P1["Project dl-shop-prod"]
  BA --> P2["Project dl-shop-dev"]
  BA --> B["Budget 500 USD / month"]
  B --> N["Alert email and Pub/Sub at 50 / 90 / 100%"]
  BA --> X["Billing export to BigQuery"]
  X --> D["Cost report by label env, team"]
  %% step BA: A Cloud Billing account holds the payment method and is linked to projects.
  %% step P1: Each project is linked to exactly one billing account at a time.
  %% step B: A budget watches actual or forecast spend for the account, projects or labels.
  %% step N: Thresholds send emails and optional Pub/Sub messages; a budget never stops resources by itself.
  %% step X: The export streams detailed usage and cost rows into a BigQuery dataset.
  %% step D: Labels such as env and team let you group the exported costs in reports.

Billing roles

Role	Can
Billing Account Administrator	Manage the account, payment, link/unlink projects
Billing Account User	Link projects to this account (with Project Billing Manager or Owner on the project)
Billing Account Viewer	Read costs and invoices
Project Billing Manager	Link/unlink one project, without seeing the account’s money

To link a project you need rights on both sides: the billing account and the project.

Budgets and alerts

A budget can cover the whole billing account or filter by project, service or label.
Thresholds use actual or forecasted spend (for example 50%, 90%, 100%).
Budgets only alert. To stop spending automatically, publish budget notifications to Pub/Sub and have a Cloud Run function disable billing or scale resources down.

Labels vs tags

	Labels	Tags
Format	`key=value` on a resource	Tag key/value resources defined at org/project level
Purpose	Cost breakdown, filtering, automation	Conditional IAM and firewall policies
Inherited?	No	Yes, down the hierarchy

Use a small, enforced label set, for example env, team, app, cost-center. Labels appear in the billing export, so SELECT labels ... SUM(cost) gives cost per team.

Saving money

Sustained use discounts apply automatically to some VM families that run most of the month.
Committed use discounts (1 or 3 years) trade a commitment for a lower price.
Spot VMs are up to 60–91% cheaper but can be stopped at any time.
Use the Pricing Calculator before you build, and Recommender to find idle VMs and oversized machines.

Command	Meaning
`gcloud billing accounts list`	Billing accounts you can see
`gcloud billing projects link dl-lab-dev --billing-account=01A2B3-C4D5E6-F7A8B9`	Link a project
`gcloud billing budgets create --billing-account=… --display-name=… --budget-amount=500USD`	Create a budget

Traps: a budget does not cap costs; labels are not inherited by child resources; unlinking billing stops paid resources and can lead to data deletion.