PAT testing logs and records.
There is no legal obligation that requires you to keep detailed records – but some system of recording what appliances have been tested, and when, is certainly a good idea.
I always supply a detailed record of what I have tested, the results of the test, and a note of any problems encountered – an example of which can be seen here… along with a sample of my atrocious handwriting.

These records should be kept safely alongside any other safety records that you have.
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