--- title: "Ad Fraud Detection for Small Advertisers: What to Check First" description: "Six checks, in the right order, for small Google Ads advertisers who want to know if fraud is costing them money. Includes a day-by-day first week plan." url: https://blockclickfraud.com/ad-fraud-detection/ date: 2026-10-09 modified: 2026-10-20 author: "Block Click Fraud" image: https://blockclickfraud.com/wp-content/uploads/2026/10/ad-fraud-detection-featured.webp categories: ["Uncategorized"] type: post lang: en --- # Ad Fraud Detection for Small Advertisers: What to Check First Ad fraud detection on a small budget starts with checks you can run yourself in Google Ads and in your server logs, done in a set order so you do not spend a week chasing noise. Begin with what Google already reports, then compare your numbers against your own normal, and only then go hunting for individual sources. Six checks, in sequence, will tell you whether you have a problem worth acting on. ## Why the order matters when budget is tight Large advertisers can afford to test everything at once. You cannot. Every hour spent reading raw logs is an hour not spent on ads that make money, and a wrong exclusion can block the customers you are paying to reach. The order below goes from cheap, broad signals to narrow, time-consuming ones. If the early checks look normal, you may be able to stop there and come back next month. ## Checks 1 and 2: Invalid clicks and conversion rate against a baseline ### Check 1: The Invalid clicks column Add the Invalid clicks column to your campaigns table (Columns, then Modify columns). It shows clicks Google's filters removed before billing, which you were not charged for. A rising count means someone is aiming more junk at your ads. It does not show what slipped past, but it tells you whether to keep digging. ### Check 2: Conversion rate by campaign Pull clicks, conversions and conversion rate for each campaign, for the last few weeks and for a comparable stretch before that. Fraud usually shows up as clicks holding steady or rising while conversions do not follow. Look campaign by campaign, because an account total can hide one campaign that went bad. If nothing moved, you may not have a problem. If one campaign stands out, focus the remaining checks on it. [High click rates with low conversions](/high-click-rate-low-conversions/) covers the other causes to rule out, such as a broken form or a landing page change. ## Checks 3 and 4: Location and hour of day ### Check 3: The location report Compare where paid clicks came from against where your customers actually are. Clicks from regions you do not serve are either a targeting problem or a fraud problem, and both cost the same. Check the campaign's location option too. The default, Presence or interest, can reach people outside your area who have shown interest in it. Presence reaches only people likely to be in, or regularly in, your target locations, and Google says it usually reduces impressions. ### Check 4: Hour of day Break clicks and conversions down by hour. Real buyers follow habits: business hours for B2B, evenings for many consumer services, a lunchtime bump for others. Clicks piling up overnight, or in a tight window every morning, with no matching conversions, point to something automated or to a person draining your budget before the day starts. ## Checks 5 and 6: Search terms and repeat sources in server logs ### Check 5: Search terms Read the search terms report for the suspect campaign. Odd, irrelevant or nonsense queries attached to paid clicks can mean loose match types, which you fix with negatives, or they can mean scripted traffic. [Negative keywords and click fraud](/negative-keywords-click-fraud/) explains where negatives help and where they do not. ### Check 6: Repeat sources in server logs This is the slowest check, so it comes last. Filter your web server logs to paid visits (those with a GCLID in the URL) and group them by IP address. Look for the same address landing again and again over several days, addresses from hosting providers rather than home or mobile connections, and visits that last a second or two with no further page loads. [How to find the IP addresses behind fraudulent clicks](/find-ip-addresses-fraudulent-clicks/) walks through it step by step. One caution: before you mark any address as bad, confirm it is not a good bot. Googlebot and AdsBot visit your pages for legitimate reasons and should stay unblocked. [Good bots you should never block](/good-bots-never-block/) lists the ones to leave alone. ## What to do with a suspect list By the end of check 6 you will have a list of addresses or ranges that look wrong. Do not exclude them all at once. Sort them into two groups: - **Confirmed:** repeated paid visits over several days, no conversions, and a pattern you can explain in one sentence. Add these to IP exclusions. Google allows up to 500 per campaign, and you can use an asterisk in place of the last digits to exclude a block. - **Suspect:** one or two odd visits, or something that might be a real customer. Watch these for another week before deciding. Write down what you excluded, when and why. If you later file a Click Quality Form request with Google, which covers only the past 60 days, those notes plus your logs supply the dates, campaigns, IP addresses and GCLIDs Google asks for. ## A realistic first week | Day | Task | | --- | --- | | Day 1 | Add the Invalid clicks column. Record clicks, conversions and conversion rate per campaign as your baseline. | | Day 2 | Review location reports and location options. Exclude regions you do not serve. | | Day 3 | Review hour-of-day data and the search terms report for any campaign that stood out. | | Day 4 | Export server logs for paid visits and group by IP address. | | Day 5 | Sort the suspect list into confirmed and suspect. Exclude the confirmed group and log it. | | Days 6 and 7 | Leave the account alone and let new data come in. | The following week, compare against day 1. If conversion rate held or improved and nothing real disappeared, you are on the right track. ## Publisher-grade ad fraud detection vs small-advertiser click protection Search for ad fraud detection and much of what you find is built for publishers and large media buyers. Those systems verify impressions across many sites and score inventory before it is bought. They are built for a different problem and priced for budgets far larger than a local business spends. A small Google Ads advertiser has a narrower question: are the people clicking my search ads real, and if not, can I stop paying for them? That calls for checking each paid click that reaches your site, blocking confirmed sources through Google Ads, and keeping records you can use with Google. When you compare options, ask which question a product actually answers. [Does click fraud protection work?](/does-click-fraud-protection-work/) takes a skeptical look. If you want this done automatically, [see how Block Click Fraud works](/how-it-works/). ## Frequently Asked Questions ### What is the first thing to check for ad fraud in Google Ads? The Invalid clicks column. It costs nothing, takes a minute to add, and shows whether Google is filtering more junk traffic than usual. A rise is a reason to keep checking. ### How do I know if low conversions are fraud or a site problem? Check the site first: test your forms, phone links and landing pages. If they work and conversion rate dropped only in some campaigns, locations or hours, fraud becomes more likely. A site problem usually hits every campaign at once. ### Can I detect ad fraud without server logs? You can get partway with Google Ads reports alone: Invalid clicks, conversion rate, location, hour of day and search terms. To find specific sources to exclude, you need IP-level data, which usually means server logs. ### Should I exclude every suspicious IP address right away? No. Exclude the ones with a clear, repeated pattern and watch the rest for another week. Excluding a real customer costs you sales you will never see in a report. ### Will Google refund clicks I prove were fraudulent? Google decides. You can submit a Click Quality Form request for activity in the past 60 days with your logs and GCLIDs. Google will not confirm which specific clicks it judged invalid, but it notifies you of any credits. ## Sources - [Google Ads Help: invalid clicks, credits and the Click Quality Form](https://support.google.com/google-ads/answer/11182074) - [Google Ads Help: about advanced location options](https://support.google.com/google-ads/answer/1722038) - [Google Ads Help: exclude IP addresses](https://support.google.com/google-ads/answer/2456098)