HMRC / DWP letters: prepare and post your correspondence

Quick answer

HMRC (the UK tax authority) accepts service complaints by post, phone or online for delays, poor communication or handling mistakes; challenging a tax decision or penalty follows a separate appeal or review route. For many DWP benefit decisions, you first ask for mandatory reconsideration, usually within one month of the decision letter date, and a posted request must arrive by then. There is no single address: use the one on your latest official letter.

This guide covers HMRC service correspondence and DWP benefit decisions that allow mandatory reconsideration. Start with your latest official letter: it identifies the office, procedure and relevant deadline. Some benefit decisions go straight to appeal or use a different process, including benefits handled by local or devolved authorities.

HMRC: service complaint or tax appeal?

For delays, poor communication or mistakes in handling your case, you can complain to HMRC by post, phone or online. Explain the events, your relevant tax reference and the outcome you want. To challenge a tax decision, bill or penalty, follow the appeal or review instructions instead; a service complaint does not replace them or extend their deadlines. Continue paying tax while a service complaint is considered unless a separate applicable arrangement permits otherwise.

DWP: check mandatory reconsideration and arrival deadline

Check that your decision permits mandatory reconsideration. You usually need to ask within one month of the date on the decision letter; a posted letter or form must arrive by then. Use the address on that letter and allow for printing and delivery. If time is short, contact the benefits office about an accepted alternative, such as phone or the Universal Credit journal where applicable. If late, contact the office and explain your good reason; acceptance is not automatic. The whole award may be reviewed and can stay the same, increase, decrease or stop.

Prepare the letter and documents

• Include your name, address, decision or correspondence date and relevant reference. For DWP reconsideration, include your date of birth and National Insurance number.
• Explain exactly what is wrong, why, and what you want the office to do. For DWP, send relevant new evidence not already supplied and label it as the official guidance requires.
• Keep copies. Check the latest official letter or contact page for the correct office; there is no single address for all HMRC or DWP matters. Printed copies cannot replace originals when the office requires original documents.

HMRC complaint letter example

Adapt the first example for a service complaint and the second only for an eligible DWP reconsideration. Replace every placeholder and check the official instructions before sending.

[Your name, address and contact details]

[Relevant HMRC office and verified postal address]

[Date] — [Relevant tax reference]

HMRC service complaint — [brief description]

Dear Complaints Team,

I wish to complain about the handling of [matter]. On [dates], [describe the delay, communication problem or handling error]. My previous contacts were [dates and references].

I would like HMRC to [requested action]. I enclose copies of [relevant documents]. Please acknowledge this complaint and explain what will happen next and when I can expect a response.

Yours faithfully,

[Your name]

Mandatory reconsideration letter example (DWP)

[Your name and address]

[Date of birth and National Insurance number]

[DWP benefits office and address shown on the decision letter]

[Date] — [Benefit and decision reference]

Request for mandatory reconsideration

Dear Decision Maker,

Please reconsider your decision dated [decision date] about [benefit]. I disagree with [specific parts of the decision] because [facts and reasons].

The outcome I am asking for is [requested change]. I enclose [relevant new evidence not already supplied] supporting these points.

[If this request is late, explain the reason and relevant dates here.]

Please confirm receipt and send me the mandatory reconsideration notice when the decision has been reviewed.

Yours faithfully,

[Your name]

Post your completed letter

Keep a copy of the letter and attachments. Proof of posting, tracking and a delivery signature record different things; none alone establishes the contents or guarantees valid legal service. Before paying, check whether the available mailing service provides the evidence and timing your case needs. Upload your completed PDF or write your letter in MaisonMail. Enter the recipient’s full address: it determines the destination. Available services, estimated delivery and the final price appear before payment.