hermes

Set up sinking funds

Sets up sinking funds for predictable irregular costs such as car repairs, gifts, insurance and travel, with monthly amounts, catch-up plans and a simple tracker.

context

Most budget "emergencies" are not emergencies: the car service, the annual insurance renewal, birthdays, school trips, the dentist, the boiler check, the summer holiday. They are predictable in amount and roughly in timing, just not monthly. A sinking fund saves a fixed amount each month for each of them, so the bill is already paid for when it arrives and the emergency fund is kept for real shocks. The common failure is a cost that is due soon with nothing saved; the plan has to handle catch-up honestly instead of pretending every fund starts twelve months out.

irregular costs

Only if [MONTHLY_BUDGET] is given: Total available each month:

task
  1. Turn each cost into a fund: name, target amount, next due date, frequency, months until next due, amount already saved.
  2. Monthly amount per fund:
  • Steady state = cost / (12 x years between occurrences), so a yearly cost / 12 and a two-yearly cost / 24.
  • First cycle = (target - already saved) / months until due. Where this is higher than steady state, show both and when it drops back.
  • Round up to a tidy figure.
  1. Add a "probably forgot" check: list 5-8 common irregular costs not in the list (for example car tyres and MOT or inspection, glasses, vet bills, annual subscriptions, gifts at work, home maintenance at roughly 1% of home value a year for owners) and ask which apply. Do not add them to the totals unless the person listed them.
  2. Total the monthly amounts. Compare with the available budget if given.
  3. If it does not fit: rank the funds (essential and contractual first, such as insurance, tax, car roadworthiness; then health; then flexible goals like travel and gifts), and show options - lower a flexible target, push a date, pay an annual cost monthly if that costs no more, or accept a smaller catch-up on one fund. Show the revised total.
  4. Where to keep it: one separate easy-access savings account with a simple ledger, or several labelled savings pots if the bank offers them. Keep it apart from day-to-day spending and from the emergency fund. No bank or app names.
  5. Tracker: a table the person can copy into a spreadsheet, with columns for fund, target, monthly amount, balance, due date, and a spend log.
  6. Rules: what to do if a cost comes in under target (roll over or move the surplus), over target (top up from flexible funds before the emergency fund), and an annual reset.
constraints
  • You give general information, not professional advice. You are not a doctor, therapist, lawyer, accountant or financial adviser, and you do not replace one.
  • Say so once, briefly, near the start: what you can help with here and what needs a qualified professional.
  • Do not diagnose, prescribe, give dosages, predict a legal outcome, or recommend a specific investment, tax position or legal action for this person.
  • When the situation is serious, urgent, high-stakes or specific to their circumstances, say which kind of professional to see and what to bring to that appointment.
  • If anything suggests immediate danger to health or safety, tell them to contact local emergency services now, before anything else.
  • Rules, prices and laws differ by country and change over time. Name the assumption you are making and tell them to check it locally.
  • Use the person's amounts and dates. If a cost has no amount or no due date, ask for it or mark it [X], and do not guess a figure silently.
  • Sinking funds are for predictable costs only. If the list includes truly unpredictable events (job loss, medical emergencies, a sudden large repair of unknown size), move them to an "emergency fund, not a sinking fund" note and explain why.
  • Show the arithmetic for each first-cycle amount.
  • No product, bank or app recommendations.
  • Separate what you verified from what you inferred. Mark inferences as such.
  • When you do not know, say "I don't know" once and state what would settle it.
output format

Your funds

Table: fund | target | due | frequency | months left | saved | first-cycle monthly | steady monthly.

Monthly total

Totals for the first cycle and the steady state, against the budget if given.

Catch-up plan

Only for funds due soon; how the amount steps down.

If it does not fit

Ranked list and the revised totals (omit this section if it fits).

Where to keep the money

Two or three sentences.

Tracker

Copyable table.

Rules

Bullets, plus the "probably forgot" question list.

1 required value still a placeholder; the assistant will ask for it.

details

kind
Prompt: a task you run by name to get one finished thing back
domain
Finance
category
Budgeting
level
Beginner
made for
Anyone, personal use, Parent / caregiver
risk
read-only
version
v1.0.1 · incubating
reviewed
2026-10-03
works in
Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Antigravity, OpenCode, Windsurf, Zed, Continue, AGENTS.md, ChatGPT, claude.ai

Edit on GitHubReport a problem

use in

Hodios CLI
npx @hermes-hq/hodios install set-up-sinking-funds --target claude-code

This entry is in the full catalog, not the curated set the skills installer and plugins carry, so install it with the Hodios CLI.

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