Google Ads API v18: What Changed and Why It Matters

Google updates its Ads API roughly once a quarter. Each update deprecates the oldest supported version and introduces changes that affect how software pulls data from Google Ads. If your agency uses any tool that connects to Google Ads — reporting dashboards, bid automation, or data pipelines — these changes affect you.

Google Ads API v18 is the current version. Here is what changed from v17, what breaks if you do not update, and why it matters for agencies doing client reporting. For GA4's equivalent API, see [how to pull GA4 data programmatically](/blog/ga4-data-api-pull-conversion-data-programmatically).

What Is The Google Ads API

The Google Ads API is the programmatic interface that lets external software read and manage Google Ads data. Instead of a human logging into the Google Ads dashboard, a server sends requests and gets campaign data back automatically.

Every reporting tool, bid management platform, and data pipeline that connects to Google Ads uses this API. When Google releases a new version, the old version eventually stops working.

Google supports three versions at any time. When v18 was released, v15 was deprecated. If your tool is still on v15, it has already stopped working. If it is on v16, it will stop working when v19 is released.

Key Changes In v18

1. Campaign Type Changes

Google restructured how campaign types are reported. Performance Max campaigns and Demand Gen campaigns have updated resource names and field structures. If your reporting tool queries campaign data using v17 field names, it will get errors or missing data for these campaign types.

This matters because Performance Max is one of the most common campaign types in India. If your reporting tool cannot read Performance Max data correctly, your client reports are incomplete.

2. Conversion Action Updates

v18 updated how conversion actions are queried. The field structure for conversion tracking changed — specifically, how primary and secondary conversion actions are distinguished. Tools that pull conversion data using v17 queries may show incorrect conversion counts or miss secondary conversions entirely.

For agencies, this means your CPA calculations could be wrong if the tool is not updated.

3. Asset Group Reporting

Performance Max campaigns use asset groups instead of traditional ad groups. v18 added new fields for asset group-level reporting, including asset performance metrics. This was limited in v17.

For agencies running Performance Max campaigns, this means more granular reporting. You can now see which assets (images, headlines, descriptions) are performing within each asset group.

4. Reach Metrics Updates

How reach and frequency are calculated changed in v18. The deduplication logic for cross-campaign reach was updated. If your tool reports reach metrics to clients, the numbers may look different after the update.

This is important to communicate to clients: "Our reach numbers may look different this month because Google updated how they calculate unique reach across campaigns."

5. Geographic Targeting Changes

v18 updated how geographic targeting data is reported. For agencies running campaigns across multiple Indian cities (Mumbai, Delhi, Bangalore, etc.), this affects how city-level performance data is pulled and displayed.

What Breaks If You Do Not Update

API Errors

Google deprecates old versions on a schedule. Once a version is deprecated, API calls return errors. Your tool stops pulling data entirely. No reports, no dashboards, no automated emails.

This is not a gradual failure. It is sudden. One day the tool works, the next day it does not.

Missing Data

Even before full deprecation, older versions may not support new campaign types or fields. Performance Max campaigns have evolved significantly. An older API version may return incomplete data.

Incorrect Numbers

Some changes in v18 affect how data is aggregated. Conversion deduplication, reach calculations, and campaign type classifications may produce different numbers on v18 compared to v17.

Migration Notes For Agencies

If your agency uses a third-party reporting tool, you do not need to do anything — the tool provider handles the migration. But you should verify:

Check Your Tool's API Version

Ask your reporting tool provider: "Which version of the Google Ads API are you on?" If they say v17 or older, ask when they plan to update. If they cannot answer, consider switching tools.

Verify Data After Migration

After your tool updates to v18, compare one month's data manually. Pull the same numbers from the Google Ads dashboard and from your tool. They should match within a small margin.

Watch For Campaign Type Changes

If your agency runs Performance Max or Demand Gen campaigns, check that these appear correctly in your reports after the update.

Why Staying On The Latest Version Matters

Google supports only three API versions at a time. When v19 is released (expected later this year), v16 will be deprecated. If your tool is on v16, it will break.

The cycle is predictable: - New version releases every 3-4 months - Oldest supported version is deprecated simultaneously - Deprecated versions stop working within weeks

Agencies that use tools which lag behind API updates face periodic reporting disruptions.

What This Means For Indian Agencies

Indian agencies are particularly affected by API changes because:

1. Performance Max adoption is high. Many Indian agencies run Performance Max campaigns for e-commerce clients. v18 has significant changes for Performance Max reporting.

2. Multi-city campaigns are common. Indian agencies often run campaigns targeting multiple cities. v18 changed geographic targeting reporting.

3. Clients check their own dashboards. Indian business owners are increasingly hands-on with their Google Ads accounts. They log in, see numbers, and compare with your report. If your tool is on an old API version and showing different numbers, the client will notice.

4. Reporting expectations are rising. Today, Indian clients expect platform comparison, discrepancy analysis, and campaign-level insights. This level of detail requires the latest API version.

Frequently Asked Questions

What is Google Ads API v18?

Google Ads API v18 is the current version of Google's programmatic interface for reading and managing Google Ads data. It replaced v17 and introduced changes to campaign type reporting, conversion action fields, asset group reporting, reach metrics, and geographic targeting data.

What happens if my reporting tool is still on an older API version?

If your tool is on a deprecated version (v15 or older), it has already stopped working — API calls return errors. If it is on v16, it will stop working when v19 is released. Even on v17, you may see missing data for Performance Max campaigns and incorrect conversion counts due to field structure changes.

How do I check which Google Ads API version my tool uses?

Ask your reporting tool provider directly: "Which version of the Google Ads API are you on?" If they cannot answer or say v17 or older, ask when they plan to update. A tool that does not keep up with API updates will break eventually.

Why do Indian agencies need to care about API versions?

Indian agencies run many Performance Max campaigns and multi-city targeting, both of which had significant changes in v18. Additionally, Indian clients increasingly check their own Google Ads dashboards and compare with agency reports. If your tool uses an old API version, the numbers will not match.

How ADsHisaab Handles API Versions

ADsHisaab pins specific API versions in its codebase. Google Ads API v18, Meta Marketing API v19.0, GA4 Data API v1beta. When a new version is released, the engineering team tests it, updates the version, and deploys the change — without any disruption to agency reporting.

Try ADsHisaab free at adshisaab.com