Short version
We use essential cookies to make BuildCompare work, and — only with your consent — Google Analytics to understand how the site is used. No advertising cookies, no cross-site profiling. You'll see a cookie banner on your first visit asking whether to allow analytics; you can reject it and the site still works. We also use Cloudflare Web Analytics, which is cookieless and runs whether you accept the banner or not.
What's a cookie? (and why does it matter)
A cookie is a small text file a website stores in your browser. Cookies can keep you logged in, remember your settings, or — in the third-party case — let advertisers follow you between sites. UK PECR (the Privacy and Electronic Communications Regulations) requires us to tell you about every cookie we set and to ask for your consent before setting any cookie that isn't strictly necessary. The same rule applies to other browser-storage technologies (localStorage, sessionStorage) when they're not strictly necessary.
Cookies we use
Essential — no consent required (and you can't opt out)
These are required for the site to work. Disabling them breaks core functionality.
| Name | Purpose | Lifetime | Provider |
|---|---|---|---|
| __Host-bc_session | Authenticated user session after magic-link sign-in. The __Host- prefix is a browser security feature that locks the cookie to this host over HTTPS only. | 24 hours / on logout | BuildCompare (first-party) |
| __cf_bm | Cloudflare bot management — distinguishes human visitors from automated bots and prevents abuse. | 30 minutes | Cloudflare |
Stored in your browser, never sent to us
For preferences and a guest basket, we use your browser's own storage (the technical name is localStorage). This data stays on your device until you clear it. We never receive it on our servers unless you take an action — for example, adding a guest-basket item to your account after you sign in.
| Key | Purpose | Lifetime |
|---|---|---|
| bc:settings:v2 | Your department selections, sort preference, distance setting, theme. | Persistent (you can clear via browser settings) |
| bc:guestbasket | Items in your basket if you haven't signed in. | 30 days from last activity, then auto-purged |
| bc:location | Your postcode or coarse location, if you've set one. | Until you clear it via Settings |
Analytics — Cloudflare Web Analytics (cookieless, always on)
We use Cloudflare Web Analytics to understand basic site usage (page views, country-level traffic, browser type) so we can improve the service. Cloudflare's Web Analytics product is cookieless:
- • No cookies are set on your device.
- • No "fingerprinting" — we don't quietly identify your device by its unique combination of screen size, fonts and plugins.
- • No cross-site tracking — Cloudflare doesn't link your visits to BuildCompare with your visits to any other site.
- • No personal identifiers stored.
Because there's no consent-requiring storage on your device, UK PECR's cookie-consent rules don't apply to this product, and it runs whether you accept the cookie banner or not. Cloudflare's documentation: cloudflare.com/web-analytics.
Analytics — Google Analytics 4 (consent-gated)
We use Google Analytics 4 (property ID G-CS5PBCH62T) for richer reporting on how visitors find and use BuildCompare — which pages they read, which suppliers they click through to, where users drop off. Google Analytics sets cookies, so we only load it after you click "Accept analytics" on the cookie banner. If you reject (or simply close your browser without choosing), no Google Analytics cookies are set and no analytics events leave your device.
Technically, we use Google's Consent Mode v2. The default consent state on every page load is analytics_storage: 'denied' — Google's tag loads but skips its cookies and personal data until you opt in. Advertising consent (ad_storage, ad_user_data, ad_personalization) is always set to denied regardless of your choice — we don't run any advertising surfaces.
| Name | Purpose | Lifetime | Set when |
|---|---|---|---|
| _ga | Google Analytics — a randomly generated client identifier so visits can be grouped into sessions. | Up to 2 years | Only after you click "Accept analytics" |
| _ga_CS5PBCH62T | Google Analytics 4 session state for this specific property. | Up to 2 years | Only after you click "Accept analytics" |
| bc_consent | Records your banner choice ('granted' or 'denied') and shares it across buildcompare.co.uk and app.buildcompare.co.uk so the banner doesn't reappear when you cross subdomains. Strictly-necessary preference cookie; never sent to third parties. A same-origin fallback copy of the same decision is also written to your browser's localStorage as cookieConsent for browsers that block cookies. | Up to 6 months (Safari ITP may shorten to 7 days) | As soon as you click either banner button |
You can change your mind at any time by clearing your browser storage for buildcompare.co.uk — the banner will return on your next visit. We're considering an in-page "manage analytics" toggle for a future release.
What we don't use
- • ❌ Advertising / retargeting cookies (Facebook Pixel, Google Ads, etc.)
- • ❌ Social-media share/tracking widgets
- • ❌ Behavioural-profiling tools
- • ❌ Cross-site / cross-device tracking
If we ever add any of the above (most likely candidate: a measurement pixel for affiliate-network attribution once we onboard Awin/Webgains), we will: (a) update this notice with the new cookies; (b) extend the cookie banner to ask for consent before any new non-essential cookie is set; and (c) give you a way to change your mind later.
How to manage your cookie choices
The fastest way is the cookie banner on your first visit — Accept or Reject. To change your mind later, clear your browser storage for buildcompare.co.uk; the banner will reappear on your next visit. You can also manage cookies directly in your browser:
- • Chrome
- • Firefox
- • Safari (Mac)
- • Safari (iOS)
- • Microsoft Edge
Blocking the essential cookies above will break sign-in, basket and CSRF protection — we'd recommend you don't. To clear our locally-stored preferences and guest basket, use the "Clear browsing data" function in your browser, or sign in to your account and use the in-app reset.
Do Not Track and Global Privacy Control
Our cookie banner is the primary mechanism by which you control non-essential cookies; on first visit you must affirmatively accept before Google Analytics sets any cookies. We now also respect Global Privacy Control (GPC): if your browser sends the GPC signal (Firefox >= 95, Brave, DuckDuckGo browser, the GPC browser extension), we treat that as an explicit objection — Google Analytics stays in "denied" state, no analytics cookies are set, and you don't see the cookie banner. We do not auto-treat the older Do Not Track (DNT) header — DNT was deprecated by the W3C in 2019 and most browsers no longer expose a user-controlled setting for it. GPC is the modern equivalent recognised by the UK ICO as a valid Article 21 objection signal.
Changes to this notice
We will update this notice if we change the cookies we use or add a new category of technology. The "Last updated" date below records when this notice was last revised. Material changes will also be reflected in our Privacy notice.
Contact
Questions about cookies or this notice? Email [email protected].
Last updated: 2026-05-19. See also: Privacy notice · Terms of service · Affiliate disclosure.