Resource · Updated 07/07/2026
Template letters
Adapt every bracketed section, delete anything that does not apply, keep copies of everything you send, and send by a method that proves the date. Plain, factual and specific beats long and outraged — these templates are deliberately lean.
1. Mandatory reconsideration request
Deadline: within 1 month of the decision letter. Guide: mandatory reconsideration.
[Your name, address]
[NI number] · [Case reference]
[Date]
Child Maintenance Service
[Address on your decision letter]
Dear Sir or Madam,
REQUEST FOR MANDATORY RECONSIDERATION — decision dated [date]
I request a mandatory reconsideration of the above decision under section 16 of the Child Support Act 1991.
The decision is wrong for the following reasons:
1. [Element, e.g. gross income]: the decision uses [figure]. The correct position is [figure/fact], evidenced by [document, enclosed].
2. [Element, e.g. shared care]: the decision applies [band]. The actual pattern is [nights/year], evidenced by [court order/diary, enclosed].
Please provide the full working of the calculation: the gross income figure used, the tax year it relates to, all deductions applied, and the shared care band used.
[If late:] This request is made outside one month because [reasons]. I ask that it be admitted late; in the alternative, I ask that the decision be revised for official error, which has no time limit.
Please issue the Mandatory Reconsideration Notice in duplicate.
Yours faithfully,
[Name]
Enclosures: [list]
2. Formal complaint with redress request
Guide: the complaints ladder and compensation.
[Your details, case reference, date]
Child Maintenance Service — Complaints
Dear Sir or Madam,
FORMAL COMPLAINT
I wish to register a formal complaint about the handling of my case.
Chronology of failures:
1. [Date] — [event: what happened / what failed, reference numbers]
2. [Date] — [event]
3. [Date] — [event]
These amount to maladministration: [delay / failure to action reported information / incorrect advice / failure to follow procedure].
Impact: [financial losses, itemised with amounts; charges incurred; hours spent; distress and any health impact].
I request: (a) correction of the outstanding failures; (b) a written explanation; (c) consideration under the Financial Redress for Maladministration scheme for the losses itemised above; and (d) your final response in writing so that I may, if necessary, refer this complaint to the Independent Case Examiner.
Yours faithfully,
[Name]
Enclosures: [list]
3. Subject access request
Response due within 1 calendar month. Guide: subject access requests.
[Your details: full name, address, date of birth, NI number, case reference]
[Date]
Dear Sir or Madam,
SUBJECT ACCESS REQUEST — Article 15 UK GDPR
Please supply all personal data held by the Child Maintenance Service relating to me and to case [reference], including but not limited to: case notes and contact history; telephone call summaries and recordings; maintenance calculation and decision records; income data obtained from HMRC and the tax years to which it relates; shared care determinations and supporting records; arrears ledgers; and enforcement records, for the period [date] to [date].
Please provide the information electronically. I look forward to your response within one calendar month as required by the Data Protection Act 2018.
Yours faithfully,
[Name]
4. Arrears breakdown demand
Send before agreeing to, or paying, any disputed arrears. Guide: arrears.
[Your details, case reference, date]
Dear Sir or Madam,
REQUEST FOR FULL ARREARS BREAKDOWN — case [reference]
Your [letter/notice] dated [date] states arrears of £[amount]. Before responding I require a complete breakdown showing:
1. each period of liability, the weekly amount, and the decision (with date) from which it derives;
2. every payment received, its date, amount, and the period/element to which it was allocated;
3. every fee or charge added, with its legal basis; and
4. a running balance reconciling to £[amount].
I do not admit the arrears figure pending this reconciliation. [If applicable:] My own records, enclosed, show payments totalling £[amount] between [dates] which do not appear to have been credited.
Please treat this letter as a dispute of the arrears figure and confirm that enforcement action will not be taken while the reconciliation is outstanding.
Yours faithfully,
[Name]
Enclosures: [bank statements/payment records]
Proof of sending
Online account messages are timestamped — screenshot them. Post: obtain free proof of postage at minimum; signed-for where deadlines are critical. Keep a single dated folder (paper or digital) of everything sent and received; future-you at a tribunal will be grateful.