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When a business begins planning a website migration, the first question asked is almost always the same: how much does a site migration cost? It is a perfectly reasonable question. But the more revealing question, and the one that shapes every conversation we have with prospective clients, is: how much is at risk if you get it wrong?
At POLARIS, we understand that no two migrations are alike. The complexity, the stakes, and the investment required all vary significantly depending on the size of the website, the scope of the change, and the performance you are trying to protect or grow.
This guide covers what drives website migration cost, how we approach a migration project, what additional services can increase the investment depending on your objectives, and why every pound spent on a professionally managed migration should be treated as a business-critical expenditure rather than a discretionary agency fee.
What Is a Website Migration?
A website migration is any significant change to a website that has the potential to affect its visibility in search engines. This can include:
- Moving to a new domain or subdomain
- Rebuilding or redesigning the site on a new platform or CMS
- Restructuring the URL architecture or site hierarchy
- Moving from HTTP to HTTPS
- Consolidating multiple websites into a single domain
- Internationalisation or localisation changes
- A full rebrand involving changes to content, structure, and domain
Each of these scenarios introduces a layer of technical and strategic complexity that, without specialist oversight, can result in lasting damage to organic search performance. The consequences are not always immediate, which makes them particularly dangerous. Traffic losses from a poorly executed migration can take months to fully manifest and, in some cases, years to recover from.
Understanding What the Investment Is Actually Protecting
Before we discuss the cost of a website migration, it is worth being clear about what that investment is protecting. The most direct way to quantify this is to look at your website’s existing organic and broader marketing performance.
The revenue your website currently generates through organic search, paid channels, direct traffic, and referrals represents the performance at risk if your migration is mishandled. That is what the investment is protecting.
For many businesses, organic search is their highest-converting and most cost-efficient marketing channel. It represents years of accumulated authority, rankings, and content performance. A poorly executed migration can dismantle that foundation within weeks of launch. Recovery, where it is achievable at all, almost always costs more in lost revenue and remedial effort than a properly resourced migration would have in the first place.
We encourage every client to review their analytics before we discuss project scope. Monthly organic sessions, revenue attributed to organic traffic, cost-per-acquisition from paid channels, all of this forms the picture of what is genuinely at stake. The migration investment is not an agency cost. It is a form of business protection, and it should be sized in proportion to what is being protected.
What Does a Website Migration Cost With Polaris?
Our website SEO migration services are priced based on the scope, scale, and complexity of each project. For us to take on a migration or migration recovery as a fully managed project, our work starts at £10,000 plus VAT. This is the minimum investment for a project in which we can genuinely take accountability for protecting and growing performance through the migration.
This starting point reflects the level of resource, expertise, and structured process required to own a site migration project end to end. When Polaris is engaged on a migration, we are accountable for the outcome, and that accountability requires a thorough, disciplined approach from day one.
Projects are scoped individually. For larger websites, enterprise-level migrations, international projects, or sites with significant organic revenue at risk, the investment will be higher to reflect the additional complexity and effort involved.
Payment Structure
Our standard payment structure is 25% of the total project budget on initiation, with the remainder structured around milestone-based payments as the project progresses through each delivery phase. This ensures that investment is aligned with delivery and that clients have clear visibility of progress before each payment milestone is reached.
Our 5 Stage Migration Process
Every migration we manage follows a defined five stage delivery framework. This is not a generic template — it is a disciplined process through which we gather the intelligence, develop the strategy, oversee implementation, and verify the outcome. The goal is not simply to retain performance, but to build upon it. You can read more about our full approach on our website migration services page.
| PHASE 01 | Site Performance Analysis
The foundational layer of any migration |
| We analyse and benchmark your SEO and onsite performance so that we know precisely what is critical to retain through the migration process. |
| This phase establishes the data baseline that every subsequent decision is measured against — covering organic performance, keyword rankings, technical health, page-level value, and content authority. |
| Without this foundation, a migration is being conducted without sight of what matters. We never begin a project without it. |
| PHASE 02 | Content Architecture and Review
An in-depth review to inform retention and growth |
| An in-depth analysis of your top performing content, proposed page layouts, and site structure within the new website. |
| We compare old versus new, and benchmark against competitors, to build a fully informed view of how to retain and increase performance through the structural changes being made. |
| The decisions made in this phase — around URL structure, content hierarchy, internal linking, and page templates — have the greatest long-term impact on organic performance of any stage in the process. |
| PHASE 03 | User Tracking and Search Engine Compliance
Ensuring you have the data to drive digital performance |
| We design and implement a tracking solution built around your digital goals, so that you have the data required to understand and drive performance post-launch. |
| This includes analytics configuration, conversion tracking, Search Console setup, and full crawl accessibility validation. |
| Search engine compliance is verified in this phase — confirming that the new site is structured and signalled in a way that search engines can understand, index, and reward correctly. |
| PHASE 04 | Technical Analysis and Changeover Report
Simulating the search engine experience before launch |
| We simulate how a search engine will crawl the new website, evaluating load speed, accessibility, and technical architecture against SEO requirements. |
| We map and deliver the full redirect set to ensure minimal 404 errors and crawl disruption at the point of changeover. |
| A full changeover report is produced and signed off before launch proceeds. This gate prevents preventable issues from going live. |
| PHASE 05 | Post Launch Monitoring and Reporting
Verifying the migration outcome over the critical post-live window |
| We manually check your website’s performance in search engines across key markets and test tracking and top-performing user journeys to confirm a successful migration. |
| Post-migration site performance is reported for up to four weeks post-launch, providing a clear and accountable record of how the migration has performed. |
| Any anomalies identified during the monitoring window are addressed promptly, with direct access to our team throughout. |
Migration Recovery: When Things Have Already Gone Wrong
Not every client comes to us at the planning stage. A significant part of our work involves migration recovery, working with businesses that have already launched a migration and experienced a material decline in organic performance as a result.
The investment for a migration recovery is consistent with our standard migration pricing, starting at £10,000 plus VAT. However, the objective and the urgency are different. When organic performance has already declined, every week without intervention represents additional lost revenue. The need to work quickly is not negotiable, and how we resource and prioritise the project reflects that.
Our Migration Recovery Delivery Framework follows five structured phases:
| PHASE 01 | Diagnostics
Identify the causes of traffic loss |
| Crawl diagnostics to identify technical failures introduced during the migration |
| Indexation comparison between pre and post-migration states |
| Ranking volatility analysis to identify pages and terms most affected |
| Template comparison to surface structural regressions |
| Internal linking audit to identify disruptions to authority flow |
| Technical regression detection across all key site parameters |
| PHASE 02 | Recovery Roadmapping
Produces the recovery strategy |
| Root cause prioritisation — establishing which issues are driving the greatest share of performance loss |
| Opportunity modelling to forecast the recovery impact of specific fixes |
| A structured recovery roadmap with clear prioritisation and realistic timelines |
| Content and technical backlog creation for phased remediation work |
| PHASE 03 | Integration Consulting
Where Polaris delivers the most value |
| Developer consulting to ensure technical fixes are implemented correctly and efficiently |
| CMS fixes to address platform-level issues introduced during the migration |
| Internal linking reconstruction to restore and improve authority distribution across the site |
| Metadata restoration across affected page templates |
| Page template fixes to resolve structural SEO regressions |
| Redirect fixes to correct broken or missing redirect chains |
| PHASE 04 | Testing and Validation
Ensuring fixes are working as intended |
| Crawl validation to confirm technical fixes have been implemented correctly |
| Redirect validation across the full redirect map |
| Indexation monitoring to track re-crawl and re-indexation of affected pages |
| Ranking recovery checks against pre-migration performance benchmarks |
| Template QA across all key page types |
| PHASE 05 | Performance Reporting
Track and communicate recovery progress |
| Recovery dashboards providing clear visibility of performance improvement over time |
| Traffic recovery tracking against pre-migration baselines |
| Ranking recovery reporting across target keyword sets |
| Stakeholder reporting to keep internal teams and leadership informed throughout |
Migration recovery is not a guaranteed outcome. The degree to which performance can be restored depends on the nature and duration of the decline, the technical state of the site, and the actions already taken. What we can commit to is identifying every recoverable opportunity and pursuing it with the speed and rigour the situation requires.
What Can Increase the Investment
The starting investment covers the core migration or recovery framework described above. Depending on your business objectives and the complexity of your project, a number of additional services can be incorporated that will increase the overall investment. These are not optional extras, they are workstreams that add genuine strategic and commercial value to the project.
Search Demand Analysis
One of the most overlooked opportunities within any migration is the chance to validate the commercial logic of the new site’s structure before it is built. Search demand analysis examines the actual volume and intent behind queries related to your products, services, and categories, so that content and structural decisions are grounded in evidence rather than assumption.
This work can inform category naming conventions, page hierarchies, and whether a proposed section of the new site has sufficient search demand to justify its inclusion. It can also surface opportunities that were not part of the original migration brief, terms your site should be targeting, or naming conventions that are misaligned with how your customers actually search. For businesses restructuring significant sections of their website, this is a high-return addition to the project scope.
Site Structure Design
Beyond content architecture review, some projects benefit from a ground-up site structure design engagement. This involves mapping the full information architecture of the new site, defining the navigational hierarchy, establishing the internal linking model, and producing a structural blueprint that development teams can build to directly.
This service is particularly valuable for large or complex websites, for businesses consolidating multiple sites into one, or for organisations where the migration is accompanied by a significant expansion or restructuring of the content estate.
Conversion Rate Optimisation
A migration creates a rare and underused opportunity to test new page layouts, calls to action, and user journeys before the new site is committed to at scale. Incorporating conversion rate optimisation into the migration project means the new site is designed to improve upon the commercial performance of the old one, rather than simply replicate it.
This can include A/B testing frameworks, heatmap and session recording setup, user journey analysis, and the design and testing of new templates for key commercial pages. For businesses where on-site conversion is a primary commercial lever, this investment often pays for itself within months of launch.
Management Level Reporting
For larger organisations, or those where a migration is a board-level priority, enhanced management reporting can be built into the project. This includes executive dashboards, regular written performance summaries, stakeholder presentations, and the translation of technical migration data into commercial language that senior leadership can act on.
This service is particularly valued by businesses where the migration is being overseen by a leadership team who need confidence that performance is being protected, without needing to engage with the technical detail directly.
International and Multilingual SEO
Migrations that involve international expansion, entry into new markets, or the restructuring of an existing hreflang implementation add a significant layer of complexity. International SEO within a migration encompasses hreflang tag implementation and auditing, geo-targeting configuration, country-specific performance benchmarking, and validation of international crawl and indexation signals across all target markets.
Without specialist management, international migrations carry a disproportionate risk of performance loss across multiple markets simultaneously, making this one of the highest-risk and highest-value additions to an international project scope.
Content Production and Optimisation
Migrations often surface content gaps, pages that need to be rewritten, consolidated, or created from scratch to serve the new site structure effectively. Where content production or optimisation is required as part of the migration, this can be incorporated into the project scope, ensuring the content estate is in the strongest possible position at launch rather than being addressed reactively in the weeks that follow.
Technical Development Support
For businesses without a dedicated development resource, or where the development team requires close technical SEO oversight throughout the build, embedded technical support can be incorporated into the project. This involves working directly alongside developers, reviewing implementation in real time, and ensuring that SEO requirements are built correctly first time rather than identified and corrected after launch.
Why Migration Investment Is Business Critical
There is a version of this conversation that treats website migration cost as a procurement decision, a line item to be minimised, compared across suppliers on price alone, and negotiated down. We understand why that instinct exists. But we would encourage a fundamentally different frame.
Any investment into a migration is a cost that must be weighed against the performance it is protecting. The question is not what the migration costs. The question is what the organic and marketing performance it protects is worth to your business, because that is the risk on the table.
A business generating £500,000 per year in revenue attributable to organic search is not making a discretionary decision when it invests in a specialist-managed migration. It is making a risk management decision. The investment is the premium on the policy.
A business that spends £8,000 on a migration managed by a generalist rather than £15,000 on a specialist-led project, and loses 40% of its organic traffic as a result, has not saved money. It has lost it, and in most cases, the ongoing cost of that loss will substantially exceed any short-term saving on the original project fee.
We have managed the recovery of migrations that were handled poorly elsewhere. The cost, measured in remedial agency fees, in lost revenue during the decline, and in the time it takes to rebuild what was lost, is almost always significantly greater than a properly resourced migration would have cost at the outset.
The right way to determine an appropriate migration budget is to look at what your website delivers commercially, understand what is at risk if performance declines, and invest proportionately in protecting it. Our team will help you work through that calculation as part of any initial project conversation.
Talk to Polaris About Your Migration
If you are planning a website migration, or if you have already launched one and are experiencing a performance decline, we would welcome a conversation. Our website SEO migration services page provides further detail on our approach, our experience, and how we work with clients across the UK and Europe.
Every project begins with a discovery conversation in which we take the time to understand your website, your performance baseline, your objectives, and the specific risks your migration presents. From that conversation, we provide a considered scope and investment recommendation.
Migrations are one of the highest-stakes events in a website’s commercial life. They deserve to be treated as such, and they deserve to be managed by specialists who understand the full complexity of what is involved.
To find out more about how Polaris approaches website migration and migration recovery, visit our website SEO migration services page or contact our team to discuss your project.
