Overtime approval record
An approval record is the ledger behind the requests. One line per occasion, showing hours asked for, hours actually worked, who authorised them and what they were for. Kept monthly, it answers questions the individual forms cannot.
Questions people ask about this letter
How long should this log be kept?
Follow your own record-keeping period. Working-time records have a statutory retention period in many countries, and it is not the same one everywhere.
What does it mean when worked hours keep exceeding authorised ones?
The estimate is wrong or the approval is a formality. Either way the gap is the finding, and it is worth more than the totals.
Should time in lieu appear in the same log?
Yes, in the settled column. Splitting it into a second sheet hides how much of the extra time is still owed.