Ahrefs vs Semrush for UK agencies: features and testing

Ahrefs and Semrush are the two platforms most UK agencies weigh up when they move from free data to a paid licence, and the decision usually turns on the work you do for clients rather than on marketing claims. This guide compares the named tools behind each subscription — Site Explorer, Keywords Explorer and Rank Tracker against Domain Overview, Keyword Magic Tool and Position Tracking — then sets out a two-week side-by-side test you can run on one client campaign, covering Google UK rank tracking, location targeting and reporting. It closes with the VAT and billing questions to settle before you sign, including Semrush's published UK VAT rules and the UK standard rate.

What each licence gives a UK agency

Ahrefs is built around a backlink index, and that is usually the first thing an agency names when it explains why it pays for the platform. Site Explorer covers backlink profiles and organic positions, Keywords Explorer handles keyword research, Site Audit crawls a site for technical problems, and Rank Tracker records positions over time. Research and reporting stay in one login, because keyword data and rank tracking sit in the same subscription.

Semrush covers similar ground through different modules. Domain Overview summarises a competitor's footprint, Keyword Magic Tool handles keyword research, Site Audit runs technical checks and Position Tracking records rankings. It also bundles paid-search data and local listings management into the same licence, neither of which Ahrefs offers in its subscription.

Both platforms let you set the search engine to Google and the location to the United Kingdom, and both report positions from a national index rather than a simulated local browser. What differs is granularity: how many locations a plan covers and how often positions refresh are set per tier, and vendors change those limits, so what you can promise a client depends on the plan you buy. Our notes on local rank tracking explain why city-level reporting changes the reports you hand over.

It also pays to know how a vendor assembles its index before you rely on it. Our guide to SEO tool data and sources lists what to check during a trial.

Run a two-week side-by-side test

One client campaign is enough to show which platform suits your work, and running the two tools side by side is the only way to compare them on your own keywords. Allow a fortnight, because a difference in refresh timing can look like an accuracy gap.

Keep the screenshots. Plan limits on tracked keywords and locations are easier to settle with a vendor when you can show the report you were trying to build. A trial also tells you whether you enjoy working in the tool, which no feature list will.

VAT and billing before you sign

UK agencies pay for these subscriptions in pounds, dollars or another currency depending on the billing entity and the payment method, and VAT treatment differs between vendors, so settle it before you commit.

Semrush states its rules for UK customers: it collects VAT from customers residing in the United Kingdom. Buy as a legal entity and give a valid VAT number and no VAT is applied to your payment; buy as an individual and VAT is charged at the rate of your country of residence Semrush VAT FAQ.

The UK standard VAT rate is 20% HMRC VAT rates, so a quoted price can grow by a fifth. If your agency is VAT-registered, VAT charged on a business subscription is normally reclaimable as input tax, but it still has to be found up front.

Ahrefs publishes no equivalent rule that can be quoted here, so put the same questions to its billing team in writing before you sign:

Client data and access

Adding a client's site to a rank tracker, or connecting their Search Console property, means your agency handles that client's data — normally as a processor, with the client as controller. That calls for a lawful basis, a written agreement covering what you do with the data and how long you keep it, and a way to answer subject access requests. The Information Commissioner's Office publishes guidance on controller and processor duties if you need the detail.

Before you hand over Search Console access, ask each vendor where data is stored, whether it is transferred outside the UK and what security certifications it holds. Your duties as a processor are the same whichever platform you buy.

Which platform suits which agency

Link-led retainers. Where competitor link profiles, link gap analysis and technical clean-ups drive the strategy, Ahrefs' backlink data is usually the feature that earns its keep, and Rank Tracker covers straightforward client reporting.

Mixed organic and paid work. Where you report on paid search alongside organic, write content briefs or manage local listings for several clients, Semrush's assembled toolkit replaces smaller subscriptions. Our guide to local SEO tools covers the listing side for high street clients.

Small agencies. One platform learned properly beats two entry-level licences. Pair it with free data such as Google Search Console and the options in our guide to free SEO tools for UK small businesses, then add a second paid seat when a client brief justifies it.

Common questions

Does Semrush charge VAT to UK customers?

It states that it collects VAT from customers residing in the United Kingdom. A business that supplies a valid VAT number is not charged VAT on its payment, while an individual pays VAT at the rate of their country of residence.

Is Ahrefs or Semrush better for tracking UK rankings?

Neither wins in the abstract. Both let you set the location to the United Kingdom, and the deciding factors are how many locations your plan covers, how often positions refresh and what those limits cost, so run the two-week test on your own keywords.

How do we compare the cost of the two licences?

Take the figures from each vendor's own pricing page on the day you buy, convert them at the rate you are actually charged and add VAT where it applies. The seats and usage limits included in a plan matter as much as the headline price.

Do we need both tools?

Rarely. Most agencies get further with one paid platform plus free data such as Google Search Console, adding the second licence only when a specific client brief justifies it.