How the 30-day complaint acknowledgement period is calculated
The 30-day date is an acknowledgement deadline for a supported UK data protection complaint. It is not a target for delaying the investigation and it is not a fixed deadline for the final outcome.
Start with the first receipt date
Record the date on which the organisation first received the complaint through any reasonable channel. Do not reset the clock when the message reaches the privacy lead or is entered into a case system.
Keep the original channel and timestamp with the record. If the date is disputed, preserve the email header, web-form receipt, postal record, call note or other evidence that supports the date used.
Count from the day after receipt
For the supported rule set, the day after receipt is day one. Count 30 calendar days. The calculation should retain both the nominal 30th calendar day and any adjusted acknowledgement deadline.
Use the calendar for the relevant UK region. England and Wales, Scotland and Northern Ireland do not always share the same public holidays, so the region selected for the case should appear in the calculation record.
Adjust a non-working deadline
If the 30th calendar day falls on a Saturday, Sunday or relevant public holiday, move the acknowledgement deadline to the next working day. Keep the nominal day 30 in the record so the adjustment can be checked.
A sound evidence file should state the receipt date, day one, the 30th calendar day, the reason for any adjustment, the adjusted deadline, the region and the bank-holiday data version used.
Acknowledge early where possible
Thirty days is the outer acknowledgement period for the supported route, not a reason to wait. A prompt acknowledgement confirms that the complaint has arrived, identifies the owner and explains what the person can expect next.
The investigation should begin on receipt and proceed without undue delay. An organisation may set its own earlier progress-review date, but that is an internal control rather than a statutory final-response deadline.
Keep other clocks separate
A complaint may also exercise a right of access, rectification, erasure or another data right. Record and calculate that request separately. The complaint acknowledgement date does not replace, extend or pause the rights-request response period.
Where the message is unclear, record the triage question and the answer. Do not make the complainant repeat information the organisation already has merely to start the complaint record.
Material reviewed for this guide
- What to do when you receive a complaintInformation Commissioner’s Office
- Data (Use and Access) Act 2025, section 103legislation.gov.uk
- UK bank holidaysGOV.UK
This guide is general operational information, not legal advice. Check the official material and obtain appropriate advice for circumstances outside the stated scope.