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Everything You Need to Know for a Successful Data Migration (+ Bonus Checklist!)

In Analytics, The Digital Marketing Blog by Ana CorvoLeave a Comment

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When it comes to migrations, the saying ‘better safe than sorry’ often comes to mind. There’s no such thing as being too careful, as one simple mishap can completely derail your new website launch. 

With the data aspects of your migration, there’s a lot to consider. Following the steps detailed in this guide will enable you to:

  1. Ensure data collection is maintained throughout the migration.
  2. Guarantee new, relevant user actions will be tracked from day 1.
  3. Set expectations for data loss if the new website loses functionalities. 
  4. Launch a GDPR-compliant website to avoid fines.

This guide is for all marketers, developers and/or business owners planning a website migration. It will be helpful for all knowledge levels and applicable for all migration types. You may find that not all migration types will require you to go through every step, but always double check. 

To understand more about what’s required from an SEO perspective, check out our Ultimate SEO Website Migration Checklist

Follow this guide or click on the banner below to download our data migration checklist:


Targets & Reporting

One of the most important aspects of having a successful data migration is being able to measure its success. Be sure to take your time to set targets that you’ll monitor closely post-migration. These agreed measures of performance will keep all parties focused on the metrics that matter most. 

Migrations can often lead to dips in traffic and/or revenue, which will need to be assessed daily to identify possible bugs or performance issues. Having measures in place to safeguard against these issues will mean you’ll be proactive and not just reactive. 

Take your performance safeguarding one step forward by configuring alerts in tools, such as Google Analytics, Search Console or Google Ads to notify you of  any issues that may require your attention. 

Configuring user behaviour monitoring tools, such as Hotjar or Microsoft Clarity, will give you the opportunity to see how users are interacting with the new website. Configuring feedback surveys will give users a chance to voice their issues. This data will allow you to quickly resolve paint points for your users . 

We also recommend you create a report to identify how the migration performed against the targets and KPIs you set at the start of your migration planning. This can be particularly valuable for demonstrating the migration’s success to key stakeholders.

For our clients, we use Google Data Studio to report on migration performance. It allows us to quickly assess if there are any traffic and/or revenue drops post-migration that require our immediate attention. Take a look at an example of one report page below. 

Performance vs Targets Migration Report

At the end of the migration, the report will give you a nice overview of performance. We often get so caught up in the post-migration activity that we don’t always take time to reflect on the positive and negative aspects of the process. Having a report allows us to do just that, while setting the scene for what comes next.

Tag Management System (TMS)

The tasks in this section need to be adapted according to the tag management software in use, e.g. Google Tag Manager or Tealium. Follow the steps below to ensure your TMS is successfully migrated.

  1. Request the developers implement the TMS tracking code on the staging website. This will ensure you can configure and test tracking changes ahead of the migration.
  2. Configure, test, and publish tag changes that are required prior to the migration. This should include any tags related to event configurations, and it will ensure you don’t lose data when you switch to the new website. 
  3. Ensure the TMS tracking code has been implemented on all pages of the new website, to guarantee all pages can be tracked. Use a website crawler, such as Deepcrawl or Screaming Frog, to find pages with missing tracking. 
  4. All tracking codes for the platforms you use must be implemented on all pages of the new website, e.g. Hotjar and Google Ads. This ensures the platforms will continue to operate after the migration.

Google Analytics

This section details all the considerations you need to follow to successfully migrate your Google Analytics tracking. 

At the time of writing this guide, we focused on Universal Analytics (UA) as many businesses are still in the process of planning their move to GA4. However, considering Google Analytics (GA4) during your migration must be at the forefront of your mind, as UA will stop collecting data on the 1st of July 2023.  

We strongly recommend that GA4 and UA are run in parallel to help you during this transition and to account for the fact that GA4 is undergoing development, with new features being added frequently. 

This next generation of Google Analytics is designed with data analysts in mind, which is one of the biggest changes we’ve seen from a Google product. Make sure you factor in learning time to understand the new measurement model and all the new features. If you want help configuring GA4 or training your team, please use the form below to contact us. We’re here to help! 

While you navigate this transitional period, you’ll need to maintain the accuracy of your UA data, and this article and checklist will help you do just that. Follow the steps below to protect the accuracy of your UA data. 

  1. Visit Admin > Property Settings > Default URL to update the settings with the new website URL. This will ensure that when you click through your page-level reports, Google Analytics is able to display your website pages correctly.  

website url

2. In your master view, create a custom ‘Exclude traffic from Hostname’ filter to ensure data from your tracking tests on the staging website doesn’t skew the data in this view. 

💡 Tip: When you write the ‘Filter Pattern’ make sure you include a backslash before every period, as this field is being validated through RegEx.


3. Create a new view with an ‘Include only traffic to the hostname’ filter that ensures only data on the staging website is included. The view will allow you to perform tests and check tracking implementations without impacting the reliability of data in your master view.

4. If new third-party payment methods are added to the new website, ensure they are added to the ‘Referral Exclusion List’, e.g. Alipay, PayPal and Klarna. This will ensure your payment service providers aren’t considered to be Referral sources.


Important: When a user uses a payment option that directs them to another website and then returns them back to your website, the session data is attributed to the Referral channel, as Google Analytics sees this payment website as a third-party. 

This means the channel that was originally responsible for the session is not credited with the session and therefore, the original channel under-reports on the traffic it’s driven to your website. 

When adding these payment websites to the ‘Referral Exclusion List’ in your settings, you will ensure the original source and medium that drove the user to the website are correctly attributed.

5. Ensure all your filters still work and update them where necessary, e.g. hostname filters will need to be updated to include the new website. This will guarantee your filters work as intended on the new website. 

6. Confirm whether website search parameters have changed on the new website and reconfigure your website search settings if they have. This will enable data to continue populating your ‘Site Search’ reports.


7. Test whether your goals are configured in a way that allows them to fire on the new website, to ensure they still record data from the intended user action. Destination goals are specifically important to check as they may need URL changes. 

8. Annotate Google Analytics with all relevant changes to the data during the migration, e.g. the website launched on X day and was down for 3 hours as a result of the migration. This will ensure when your teams conduct analysis, they have the context of the changes to the data they’re using.


9. On launch day, conduct data safeguarding checks to ensure all data is being recorded and sent to Google Analytics correctly. At this point, this is only a precaution because all previous tasks have created the foundation for a successful migration that maintains all data. 

General Data Protection Regulation (GDPR) Compliance

This section focuses on ensuring your website remains compliant throughout your migration. Unlawfully collected data could result in trouble with the data protection authorities. We’d advise that you seek legal advice for this part of the process, although there are still a couple of things you can do yourself.

  1. Ensure the new website isn’t collecting and sending Personally Identifiable Information (PII) to Google Analytics. Typically, this is information like email addresses and phone numbers that can often be accidentally collected through transaction tracking, custom dimensions, event tracking or page view tracking. 

If your business is collecting PII, you can be fined by the ICO (Information Commissioner’s Office) and your customers can request compensation. Your Google Analytics account could be terminated, and your data destroyed, if you use any unlawfully collected data. 

Important: This action alone doesn’t ensure you’re GDPR-compliant. If you find you’re collecting PII, to make you truly compliant, you must implement a development fix to ensure the data cannot be collected. 

💡 Tip: Examples of where to look for PII in your Google Analytics data: Search for name=|email=|@|address=|tel=|mobile= in your ‘all pages’ report; event category, actions and labels; and all your campaign parameters.

2. Ensure the Consent Management Platform (CMP) that’s implemented on the new website is GDPR-compliant. You may be surprised to hear this, but CMPs aren’t inherently compliant after implementation, and there’s a lot of customisation that needs to happen before a solution can be deemed as compliant. Shocking, we know. 

You’ll need to ensure that your CMP isn’t firing non-essential cookies prior to a user’s consent, that it allows users to manage their  and that opting-out at any time is easy. These are just 3 examples of requirements for compliance, but if you’d like to learn more, be sure to contact us

Implementing a compliant CMP will be a team effort involving your legal, marketing and development teams. If you’re looking to build a custom CMP, your design team’s involvement will also be crucial to improve usability and opt-in rates. 

It will be important for you to manage your team’s expectations about data collection volumes, as being compliant means you won’t be able to collect data 100% of your website users. Your Analytics data remains an invaluable source of marketing insight and your website will start respecting your users’ rights, so it’s a very positive change. 

As technologies are adapting to new privacy laws, more and more solutions are becoming available to increase data collection whilst protecting your consumers’ privacy. As an example, GA4 is now using data modelling to fill in the conversion gaps from users who didn’t consent by looking at the patterns of those who did.

The right solution for your business won’t be the same as for other businesses, so make sure you take the time to go through this process mindfully, and as soon as possible to avoid fines or legal action being taken against your business.


When it comes to your campaigns on Google Ads or Social platforms, be sure to update URLs in case of URL changes during the migration. 

This will ensure campaign performance isn’t impacted because you’ve used URLs with redirects, which are forbidden by some platforms (e.g. Facebook Ads). Redirects provide a poor user experience and have a history of being used to send users to adult, dating, or other forbidden content that violates the platforms’ advertising policies.

Ready for a Successful Migration?

Whether you are a marketer, developer or business owner, make sure you factor in enough time to consider all data aspects of your migration. A planned migration will be a successful migration! 

Download the checklist below and share it with your team:


Thinking of undertaking a website migration and looking for support? We’ve got a whole host of experience when it comes to migrations and you can find out how we managed Dunelm’s most successful migration in their history here.

You can also find out more about our Website Migration services here and listen to a podcast with our MD, Scott Colenutt on how to ensure your website migration goes smoothly here.

Alternatively, just leave us a message via the contact form below or give us a call on 01273 733433. A migration is a critical time for any business and we’d love to ensure it’s a success!

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