Cookies can be used to store users preferences and other information about visits and actions. Cookies come in two flavours, first-party and third-party. First-party cookies are set by the site or application you are visiting and can only be read by them. Third-party cookies are set by a different web site or application than the one you are currently visiting. They are generally used to track users between different web sites and applications and to display more relevant advertising. Additional cookie information is available from our main cookies page.
The following tables explain the cookies used, what they are for and when they expire:
First-party cookies
| Name | Domain | Expires | Category | Source | Purpose |
|---|---|---|---|---|---|
| WebPageCaching | contact-forms.ordnancesurvey.co.uk | 13 hours | Caching |
Third-party cookies
| Name | Domain | Expires | Category | Source | Purpose |
|---|---|---|---|---|---|
| Dynamics365PortalAnalytics | contact-forms.ordnancesurvey.co.uk | 3 Months | Strictly necessary | Microsoft | Used by PowerPages to track usage. |
| ARRAffinity | contact-forms.ordnancesurvey.co.uk | Session | Strictly necessary | Microsoft | When using Microsoft Azure as a hosting platform and enabling load balancing, this cookie ensures that requests from one visitor's browsing session are always handled by the same server in the cluster. |
| ARRAffinitySameSite | contact-forms.ordnancesurvey.co.uk | Session | Strictly necessary | Microsoft | When using Microsoft Azure as a hosting platform and enabling load balancing, this cookie ensures that requests from one visitor's browsing session are always handled by the same server in the cluster. |
| timezoneoffset | contact-forms.ordnancesurvey.co.uk | Session | Strictly necessary | Microsoft | Time zone |
| isDSTSupport | contact-forms.ordnancesurvey.co.uk | Session | Strictly necessary | Microsoft | Time zone |
| isDSTObserved | contact-forms.ordnancesurvey.co.uk | Session | Strictly necessary | Microsoft | Time zone |
| ContextLanguageCode | contact-forms.ordnancesurvey.co.uk | Session | Strictly necessary | Microsoft | |
| timeZoneCode | contact-forms.ordnancesurvey.co.uk | Session | Strictly necessary | Microsoft | Time zone |
Last audited on: 27 August 2025