UK GDPR: ‘lawful basis’ for processing personal data

Under the UK GDPR, you must identify a lawful basis (legal reason) you can use to justify the specific purpose for processing personal data. Use our guidance to work out which of the 6 lawful bases to use and avoid wasting time seeking consent you don't need.

Last reviewed on 30 September 2026See updates

School types: All•School phases: All•Ref: 34542

Contents

You must identify a lawful basis to process personal data
Use the Information Commissioner’s Office (ICO)'s self-assessment tool
You need to meet additional conditions for processing special category data
Next steps

You must identify a lawful basis to process personal data

For all data processing activity you do under the UK General Data Protection Regulation (UK GDPR), you must identify a 'lawful basis' to justify the specific purpose for processing personal data.

If you use the same set of data for more than 1 purpose, you must identify a legal basis for each specific purpose.

You'll have to decide which basis to use on each occasion, based on the context and details of your processing activities.

Your processing must always be ‘necessary' and 'proportionate’

This follows the 7 principles of data processing under the UK GDPR – get further

You must identify a lawful basis to process personal data

Your processing must always be ‘necessary' and 'proportionate’

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