What it does with "I want to put the rent up in January"
You type:
"Monthly tenancy, rent £950 due on the 20th. Started 20 March 2024, last increase 20 January 2026. I'd like £1,000 from January. What do I need to do?"
↓ and get back
The dates
2 months' notice from service · 52 weeks after the tenancy began (met) · 52 weeks after 20 January 2026 = 19 January 2027 · must start on a rent day (the 20th).
Earliest start: Wednesday 20 January 2027.
Serve Form 4A by hand by Friday 20 November 2026, or post it a few working days earlier.
Increase: £50 a month (5.3%), £600 a year. Check 3–5 similar homes nearby on the portals before you settle on the figure.
For you
- Form 4A from gov.uk, unchanged: 4.1 £950, 4.5 £1,000 (per month), 4.2 20/03/2024, 4.3 20/01/2026.
- A short message to talk it through with your tenant first.
- A friendly covering letter to go with the form.
- Diary: serve by 20 Nov, keep proof, new rent 20 Jan 2027, next possible rise 20 January 2028.
Every date is worked out from what you typed. Comparable rents come from you, never made up.
The free skills
rent-increase
The four Section 13 date rules (2 months from service, not in the first year, once every 52 weeks, on a rent day), the last day to serve by hand or post, a check of your figure against open-market rent and the tribunal, Form 4A question by question, and a covering letter that never replaces the form.
repair-requests
Safety steps first for gas, CO, fire and leaks, then an urgency tier with a target timescale, whose job it is (gov.uk's list of landlord repairs), damp and mould handled cause-first, 24 hours' written notice for access, a contractor brief, and a dated repair-log row.
tenant-messages
Pet requests answered within 28 days with a fair reason, a tenant's notice checked against the rent day, inspection notices, a first friendly note about late rent with no threats, noise complaints with safeguarding in mind, welcome messages and fraud-safe changes of bank details.
Free landlord tools and guides
- Section 13 rent increase date calculator: the earliest start date and the last day to serve Form 4A, with a covering letter
- Making Tax Digital for landlords: the £30,000 test: are you in from April 2027? A calculator with worked examples
- Gas safety certificate renewal: the next due date, the early window that keeps it, and tenant access letters
Set it up (no coding, about 3 minutes)
1. Grab two things: the instructions and the guide (one file).
On a phone? Open the instructions and copy them from there.
2. Make your assistant in the app you use.
- In ChatGPT, click GPTs in the sidebar, then + Create.
- Open the Configure tab. Name it
Landlord Assistant. - Paste the instructions into Instructions (Ctrl+V, or ⌘V on a Mac).
- Under Knowledge, click Upload files and add
landlord-assistant-guide.md. - Click Create, choose Only me, and save. It's in your sidebar now.
Making a GPT needs a paid ChatGPT plan. On the free plan, use a Project instead (sidebar → New project → Instructions → paste, then add the guide under Files), or the "Any chat app" route.
- In Gemini, open Explore Gems in the sidebar, then New Gem.
- Name it
Landlord Assistant. - Paste the instructions into Instructions.
- Under Knowledge, add
landlord-assistant-guide.md. - Click Save. Find it later under Gems.
- In Claude, open Projects, click New project and name it
Landlord Assistant. - Click Set project instructions, paste the instructions and save.
- Under Project knowledge, click + and upload
landlord-assistant-guide.md. - Start every chat inside the project.
Works in any AI chat app, including free plans and Microsoft Copilot. No setup, just a little more pasting each time:
- Start a new chat and attach
landlord-assistant-guide.md(the paperclip or + button). - Paste the instructions, then add your request on the next line.
For Codex, Cursor, Gemini CLI, Copilot and other coding agents:
npx skills add polytheseus/landlord-skills
In Claude Code: /plugin marketplace add polytheseus/landlord-skills then /plugin install polytheseus-landlord@landlord-skills.
3. Ask it something: "Tenant texted: 'black mould is back in the baby's room'. Write a reply and tell me what to do this week." Or: "Rent £950 due on the 20th, last rise 20 Jan 2026. When can the next one start?"
Keep it private: Use first names and the facts only. Never paste tenants' bank details, dates of birth, ID or immigration documents. Check your AI app's data settings too.
Menus in your app may look slightly different. Full written steps, with every button named: SETUP.md.
Landlord Skills Pro
The three free skills plus six more, covering the whole tenancy from advert to check-out:
🔑 New tenancy
An advert with one fixed rent (no bidding, no blanket bans), the money rules before move-in (nothing before signing, at most a month in advance, the 5-week deposit cap with the maths), written information before signing, right to rent, a dated before-the-keys checklist and a welcome pack.
💷 Rent arrears
A running arrears statement, then the letters in the right order, from a friendly check-in to a final letter, a repayment plan that adds up, Universal Credit managed payments, and a plain explanation of grounds 8, 10 and 11 (3 months' or 13 weeks' rent, Form 3A, 4 weeks' notice). No threats, ever.
🧾 Deposit deductions
Check-in against check-out, room by room. Fair wear and tear left out, replacements apportioned by age (no betterment), a polite proposal email, the 10-day return, and a tidy statement for the scheme's free dispute service.
📅 Compliance calendar
Gas every 12 months (booked inside the 2-month early window), EICR every 5 years, EPC, alarms, deposit, licences, rent review and tax dates for each property, overdue items first, plus a file to import into Google Calendar or Outlook.
🗂️ Landlord database ready
The new "Register your rental property" service: your region's 3-month window (West Midlands first, from 15 December 2026), the £65 a year per property fee, and a per-property checklist of certificates and details, with anything out of date flagged.
📊 Year-end records
Paste a year of rental bank lines and get them sorted into HMRC's categories, repairs and improvements separated, mortgage interest kept apart as finance costs, the £1,000 allowance compared, and questions for your accountant.
Plus a 10-prompt pack that works in any AI chat app with no setup.
£19 / $24 / €22, paid once. You get every future update free.
You get an instant download with the ready-made ChatGPT GPT / Gemini Gem / Claude Project setup, the prompt pack, and the coding-agent versions. England only; rules checked against gov.uk on 30 October 2026. Not legal or tax advice. Checkout, VAT and sales tax are handled by Polar, the merchant of record. Refunds within 14 days, see the terms.
UK Landlord Records Spreadsheet
Keeping the books for your lets? Our spreadsheet does the adding up:
- Rent and expenses per property, with your share of jointly owned lets.
- Quarterly totals that match the Making Tax Digital update periods, in HMRC's categories.
- Mortgage interest kept separate (it gets 20% relief, not a deduction), and SA105 box totals for the return.
- Works in Excel and Google Sheets.
£14 one-off, instant download
Checkout, VAT and sales tax are handled by Polar, the merchant of record. Refunds within 14 days, see the terms.
Questions
Is it free?
Yes. The three skills are free and open source (MIT). You need ChatGPT, Gemini or Claude; on a free plan, use the "Any chat app" route above. Landlord Skills Pro adds six more (new tenancies, arrears, deposits, a compliance calendar, the landlord database and year-end records) for £19, paid once.
Does it work in Wales, Scotland or Northern Ireland?
The tenancy rules are written for private tenancies in England under the Renters' Rights Act 2025, in force from 1 May 2026. Wales (Renting Homes), Scotland and Northern Ireland have different laws, and the skills say so instead of applying England's rules.
Can I still use a rent review clause?
No. Since 1 May 2026 the rent can only go up with a Section 13 notice on Form 4A, at most once a year, with at least 2 months' notice, starting on a rent day. You need the form even if the tenant agrees. Source: gov.uk landlord guide.
How long do I have to answer a tenant's pet request?
28 days, in writing. You can ask for more information within those 28 days; once you get it, you have the rest of the 28 days or 7 more days, whichever is later. A refusal needs a reason, and assistance animals shouldn't be refused.
How fast do I have to fix a repair?
The law says "within a reasonable time" of being told, and that gets shorter as the risk grows. The repair-requests skill uses good-practice targets: make emergencies safe within 24 hours, urgent jobs in 3–5 days, routine ones in 2–4 weeks. A faulty smoke or CO alarm must be repaired or replaced as soon as reasonably practicable.
Is it legal advice?
No. The skills draft and you decide. They follow gov.uk guidance and tell you what to check, but they don't replace a solicitor or a letting agent, and disputes or possession need proper advice.
Who makes this?
Polytheseus: skill packs written by an AI agent (Claude) and checked against official sources. The source is on GitHub. Corrections are welcome at [email protected].