# Ad Verification With a Proxy: A Step-by-Step Check | ProxyJam

Ad verification with a proxy: see the placement, creative and landing page a market is served, record each check, and spot partner cloaking and misplacement.

- Canonical: https://proxyjam.com/blog/ad-verification-proxy-guide/
- Updated: 2026-10-20
- Language: en

Ad verification is checking that a campaign ran on the terms the advertiser bought: placement, creative, landing page and market. To check it, load the placement in that market from a static address on an internet provider's network, in a browser never signed in to the ad platform. Record every run the same way (screenshot, redirect chain, time, address used) and compare runs. Where your record and a partner's report differ, you have a finding.


## Run and record one check

1. **Confirm the address** Open [What Is My IP](/what-is-my-ip/) through the proxy and note the address, its country and its network.
2. **Open the clean profile** Start the browser profile kept for checks, signed in to nothing, with the developer tools open and Preserve log ticked on the Network panel.
3. **Load the placement** Open the page the campaign bought and wait for the ad to render. Take a screenshot of the browser window with the address bar in view, and a full-page capture of the page.
4. **Follow the ad** Click the ad once, on a campaign you or your client bought, and let the landing page load. A click on a live ad can be counted and billed, so one per run is the ceiling. Export the session as a HAR file.
5. **Write the run down** Record the UTC time, the address and its network, the placement, the creative you saw and the landing page you reached, next to what the campaign plan says.
6. **Repeat on schedule** At the next scheduled time, run the same steps from the same address and compare the two records.

## What a mismatch points to

|  | What the record shows | What to ask the partner |
|---|---|---|
| Landing page differs from the approved one | The click from the market ends on a page or product other than the one submitted | Which redirect sends the audience elsewhere, and who controls it |
| Same click, different pages by network | A hosting address reaches the approved page and an internet provider's address reaches another | Why the destination treats visitors differently by network |
| Unknown hops in the redirect chain | Domains between the click tracker and the final page that the tracking plan does not list | What each extra hop is for, and who added it |
| Ad on another domain | The page in your screenshot is not the domain in the delivery report | Whether the seller appears in that publisher's ads.txt file |
| Hidden or stacked ad | The ad loads but sits under another ad, off screen or in a one-pixel frame | How the slot was rendered, and whether those impressions were filtered |
| Wrong market | The ad appears in an excluded country, or is missing from a bought one | Which geo settings the line item carried |
| Competitor in an exclusive slot | Another advertiser's creative fills a slot sold as exclusive | How competitive separation was set for the placement |

Each row pairs a sign with the document that names it: the IAB/MRC ad verification guidelines, the MRC invalid-traffic standard, Google's cloaking policy or the IAB Tech Lab ads.txt specification. A sign is a reason to ask the partner and proves nothing on its own. We have measured no ad system ourselves.


## Quick answers

### Is ad verification through a proxy allowed?

Under our Acceptable Use Policy, yes. Ad verification is named among the permitted uses (section 1) and needs no prior review (section 2). The same policy prohibits generating artificial traffic, clicks or impressions, and bypassing bot-detection systems (section 5). Your campaign contract may set its own rules for testing a seller, so read it before you start.

### Will my checks count as impressions?

They can. Every load of a live placement may be counted, which is why a schedule should stay small. The MRC lists known monitoring and testing automation among the invalid traffic that measurement should filter, and a check filtered out of the delivery count is the right result.

### Can I verify a campaign targeted at one city?

Not reliably, with any proxy. Our catalogue is sold by country and named provider, and the IAB/MRC guideline calls IP location finer than a US television market questionable. Check city-level delivery with the campaign's own measurement.

### Do I need a residential address, or will a datacenter one do?

For any placement filtered by traffic quality, use an address registered to an internet provider. Under the MRC standard, known data-center traffic is filtered by routine means, so a check from a hosting range can come back empty for reasons unrelated to the campaign. A datacenter address is still useful as a second vantage point when you test for cloaking.

### Should the address rotate between checks?

Not for this job. A fixed address is what makes two runs comparable. Rotation suits many independent samples of one placement, a different exercise that also adds impressions, so run it separately if you need it.

### How long should I keep the records?

The IAB/MRC guideline suggests at least 60 days from the first report, 12 months where the records show a material error or suspected fraud, and until any dispute is resolved.


## Sources

- [IAB/MRC: Guidelines for the Conduct of Ad Verification (2012)](https://www.mediaratingcouncil.org/sites/default/files/Standards/Ad-Verification-Guideline-for-the-Conduct-of-2.pdf), the definition of ad verification, its five service lines, the limits of IP location, data capture, altered evidence and record retention
- [MRC: Invalid Traffic Detection and Filtration Standards Addendum (2015, updated 2020)](https://www.mediaratingcouncil.org/sites/default/files/Standards/IVT%20Addendum%20Update%20062520.pdf), known data-center traffic as general invalid traffic; monitoring and testing automation, hidden and stacked ads and domain misrepresentation as sophisticated invalid traffic
- [MRC: Standards and Guidelines](https://www.mediaratingcouncil.org/standards-and-guidelines), the index both MRC documents are published from
- [TAG: Eliminate Fraudulent Traffic](https://www.tagtoday.net/fraud), the Certified Against Fraud programme and its monthly Data Center IP List
- [Google Ads: Circumventing systems policy](https://support.google.com/adspolicy/answer/15938075?hl=en), the definition of cloaking and the variations by language and location it allows
- [IAB Tech Lab: ads.txt and app-ads.txt](https://iabtechlab.com/ads-txt/), how publishers declare the companies authorised to sell their inventory
- [Chrome DevTools: Network features reference](https://developer.chrome.com/docs/devtools/network/reference), Preserve log and HAR export




Ad verification, in the words of the industry guideline that set it out, is "a
process which attempts to verify that one or more attributes of a served online
ad have been executed in a manner consistent with the terms specified by the
advertiser or agency". This guide covers the part an advertiser or agency can
run itself: loading a placement from the market it was bought for, and keeping
a record that holds up when a partner disputes it. ProxyJam sells static
residential (ISP) proxies, the kind this guide describes for ad verification,
and the product side is on our
[ad verification page](/solutions/ad-verification/). Our
[editorial policy](/editorial-policy/) explains how articles like this are
sourced and corrected.

## What does an advertiser need to see?

Four things, and a partner can get each of them wrong without the advertiser
noticing from the office. The Interactive Advertising Bureau (IAB) and the
Media Rating Council (MRC) organise their
[Guidelines for the Conduct of Ad Verification](https://www.mediaratingcouncil.org/sites/default/files/Standards/Ad-Verification-Guideline-for-the-Conduct-of-2.pdf)
(2012) around five service lines: site context, geo-targeting, ad placement,
competitive separation and fraud detection. A check by hand covers them through
these four.

- **Placement.** The page the ad appeared on, its position there and what sat
  next to it. An ad sold as a slot on one site that turns up on an unrelated
  one, or beside content the brand excluded, is a placement failure.
- **Creative.** The exact asset and copy that was served. A swapped or outdated
  creative shows up here, and so does a competitor's ad in a slot sold as
  exclusive, which the guideline calls competitive separation.
- **Landing page.** Where a click on the ad leads, through every redirect. The
  final page should be the one the advertiser approved, selling the same
  product.
- **Geo targeting.** Whether the market that was bought was served. The
  guideline is frank about locating visitors by IP address: results that
  separate US from non-US traffic "are often quite accurate, those below DMA
  level are questionable". A DMA is a US television market, which is larger
  than most cities.

A single check cannot tell you how much of the campaign went right. Delivery
share, reach and invalid-traffic rates come from the campaign's own
measurement. A check by hand answers a narrower question: was this served,
here, at this time?

## Why is the office the wrong place to check from?

The office is in one market and the campaign usually is not, so the geography
is wrong from the first request. Ad systems also know the advertiser. A browser
signed in to the ad platform, or an address with the advertiser's history on
it, may be served something other than what the audience gets. The check means
something only when the ad system treats the request as one from the audience.

## How do you choose the market and the network?

Choose the country the campaign bought, then a network an ordinary household
there would use, then keep the address fixed.

### The market

Our catalogue is sold by country, with a named provider behind every address.
If the campaign targets a country, an address in that country answers the
question. If it targets one city, no proxy product can promise a vantage point
inside it, ours included. The IAB/MRC guideline itself treats IP location
finer than a television market as questionable, so a city-level finding needs
the campaign's own measurement. For the United States, the
[US ISP proxies page](/isp-proxies/usa/) lists the 24 named
carriers our addresses are registered to.

### The network

Use an address registered to an internet provider, the kind of network a
household in the market would be on; an [ISP proxy](/blog/what-are-isp-proxies/)
is that kind of address served from a data centre. The MRC's
[invalid-traffic standard](https://www.mediaratingcouncil.org/sites/default/files/Standards/IVT%20Addendum%20Update%20062520.pdf)
lists "known invalid data-center traffic" among the general invalid traffic
that measurement filters by routine means, and the Trustworthy Accountability
Group (TAG) produces a [Data Center IP List](https://www.tagtoday.net/fraud)
each month so that its members can filter such addresses. A check from a
hosting range may be served nothing, served a filler, or not counted at all,
and an empty slot of that kind tells you nothing about the campaign. An address
on an internet provider's network removes that one ambiguity. It does not make
the check invisible, and a verification check has no reason to be.
[Residential against datacenter proxies](/blog/residential-vs-datacenter-proxies/)
walks through the public registration record such filters read.

### Keep the address fixed

Use the same address for the same market on every run. Verification is a
comparison: this week against last week, one placement against another. If the
address moves between runs, a change in what you see may come from the network
and say nothing about the campaign. An ad verification proxy should therefore
be a static one, held for the whole period you pay for, which is how
[our ISP proxies](/isp-proxies/) are sold.
[ISP against rotating residential proxies](/blog/isp-vs-residential-proxies/)
compares holding one address with drawing from a pool.

## How do you prepare the browser?

Set the browser up the way the audience's is likely to be, so that what it
receives is what the audience receives.

- Keep a separate browser profile for checks that has never signed in to the ad
  platform, the advertiser's site or the advertiser's accounts.
- Match the device type to the placement: desktop inventory from a desktop
  browser. Placements bought on mobile carriers need a carrier connection,
  which a static ISP address is not.
- Set the browser's language to the audience's, since language is a common
  targeting setting.
- Before the first run, open [What Is My IP](/what-is-my-ip/) through the
  proxy. It prints the address, its location and its network, which go into
  every record.

## How do you run the check and record it?

Run every check the same way, and record it so that someone who was not there
can see what you saw. The IAB/MRC guideline is blunt about evidence:
"Conjecture or verbal evidence is not considered acceptable for ad
verification." The steps of a single run are listed under Run and record one
check. Each record holds five things.

1. **Screenshots**: one of the browser window with the ad in place and the
   address bar in view, and a full-page capture of the page. Keep the original
   files. If you mark them up, save the annotated copies
   separately, since the guideline asks that any altered evidence be disclosed.
2. **The redirect chain.** Tick Preserve log on the Network panel of the
   browser's developer tools, so that requests survive page loads, then click
   the ad. Chrome's
   [Network panel](https://developer.chrome.com/docs/devtools/network/reference)
   exports the session as a HAR file, and its default export leaves out
   cookies and other sensitive data, which suits a file you will send to a
   partner.
3. **The time**, in UTC, so that runs made from different time zones line up.
4. **The address used** and the network it belongs to, copied from the check
   page you opened before the run.
5. **What the campaign said should happen**: the placement, the creative and
   the approved landing page, taken from the insertion order or the
   trafficking sheet.

Keep the records. The guideline suggests that verification records be kept
for at least 60 days from the first report, and evidence of material errors
and suspected fraud for 12 months.

## How do you spot cloaking and misplacement by a partner?

Compare the record with the plan. Most failures surface as a mismatch between
the two, and the table What a mismatch points to lists the common ones with the
question each one raises.

Cloaking is the clearest case. Google's
[advertising policy](https://support.google.com/adspolicy/answer/15938075?hl=en)
defines it as "showing different content on your website to different people
or to Google to try to hide things that might break Google Ads' rules". A
partner who cloaks shows reviewers and the advertiser a compliant landing page
and shows the audience something else. Two comparisons point to it: the landing page
reached from the market differs from the one the partner submitted, or the same
ad resolves to different pages from a hosting address and from an internet
provider's address. Small differences are normal. Google allows a page to vary
by language or location as long as the product promoted is the same for
everyone, so the test is whether the product changed.

Misplacement shows in the placement record. An ad on a domain other than the
one in the delivery report suggests the inventory was misrepresented. A
publisher's [ads.txt file](https://iabtechlab.com/ads-txt/) declares the
companies it authorises to sell its inventory, so you can check whether the
seller named in your report is on it. Ads hidden, stacked under another ad or
served in a one-pixel frame appear in the MRC's list of sophisticated invalid
traffic. An ad served in an excluded market, or missing from a bought one, is a
geo-targeting failure.

When you find one, report it through the channel the campaign contract names
and attach the records. The guideline holds verification services to a rule
worth copying. Testing a seller without its participation is authorised only
where the campaign terms do not prohibit it. Even then, the client must have
told the seller in advance, or the verification partner must already be
approved to work in that seller's environment.

## How many addresses does a verification programme need?

One per market, plus any you add for parallel work. No count fits every
programme, but four questions settle it.

- **How many markets?** Each country you check needs its own address in that
  country, so a campaign running in three countries needs three.
- **How much runs at once?** One person working through the markets in turn
  needs no more. Two people checking the same market at the same moment can
  share an address: each one carries up to 100 concurrent sessions, dropping to
  10 once it has transferred 50 GB in a calendar month
  ([Terms of Service](/terms-of-service/), section 2.4).
- **Do you compare networks?** A cloaking test needs a second vantage point of
  a different kind, such as a hosting address. A second address of the same
  kind adds nothing to it.
- **How often?** Checking more often reuses the same address at shorter
  intervals, and frequency alone adds no addresses. Keep the schedule and the
  sample no larger than the check needs. Every load of a live placement can
  count as an impression, and section 5 of our
  [Acceptable Use Policy](/acceptable-use-policy/) prohibits generating
  artificial traffic, clicks or impressions.

The MRC lists known monitoring and testing automation among the invalid
traffic that measurement should filter, which is the right outcome for a
check. It belongs in your verification record, and the delivery the advertiser
pays for should leave it out. Addresses are priced per IP per period, as listed
on the [pricing page](/pricing/).

## When does a proxy check not answer the question?

- **Carrier-targeted mobile placements.** They need a carrier connection, and
  we do not sell mobile addresses yet. The
  [mobile proxies page](/mobile-proxies/) explains how they work.
- **City-level targeting.** A country-level address cannot confirm it.
- **Delivery share, reach and invalid-traffic rates.** These need the
  campaign's own data and a measurement vendor accredited for them.
- **Testing an ad network's defences.** Getting past its review or its bot
  detection is not verification, and section 5 of our Acceptable Use Policy
  prohibits it.

For a campaign in the United States, the
[US ISP proxies page](/isp-proxies/usa/) lists each named carrier, and one
static residential proxy for ad verification per market is where a programme
starts. The catalogue covers 77 countries, priced on the
[pricing page](/pricing/), and the [ad verification page](/solutions/ad-verification/)
answers the questions a buyer asks before ordering.

