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ConceptA tool I would build. Not client work.

Lease reader and deadline calendar

Every lease has a registration deadline, a deposit rule, an EPC to show and an indexation date. They live in PDFs and in someone’s memory, and the one you miss is the one with a fine on it.

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Concept

Not client work
What this is
A tool I would build, drawn to show the idea. Nobody has bought it, and every name and number on these screens is invented.
For
A letting agency or property manager in Belgium with a few hundred leases.
The money
In Flanders a lease has to be registered within two months of signing (FOD Financiën (opens in a new tab)), a deposit may be at most three months’ rent (Vlaanderen.be (opens in a new tab)), and renting out without a valid EPC risks a fine of €500 to €5,000 (Vlaanderen.be (opens in a new tab)).
Belongs to
Internal toolsNearest thing I have made: Rental application desk (Own product · Prototype, not shipped)
Drawn
11 Nov 2026 · sheet 1 of 6

Live demo

Drop a lease. Watch the deadline find you.

Press play, or step through it field by field. Pick any field to see where it was read, check the handwritten date, and make the deadline a task.
Demo Lettings
Portfolio48
New leases1
Deadlines6
Indexation3
Rules by region
Flanders
Brussels
Wallonia
Sofie VoorbeeldProperty manager
New leasesNew lease
Fields 0/9To check 0Read by AISave to unit
huurovereenkomst-voorbeeldlaan-12.pdfp. 1 and 4 of 4

Drop a signed lease here

huurovereenkomst-voorbeeldlaan-12.pdf · 4 pages

What was read

Pick one to see it on the page

Rules for Flanders

Checked against what was read
  • DepositWaiting for the fields it needs
  • EPCWaiting for the fields it needs
  • IndexationWaiting for the fields it needs
  • RegistrationWaiting for the fields it needs

Dates from this lease

  1. 18 SepSigned
  2. 18 NovRegister the lease, in 7 days
  3. 1 Oct 2027First indexation

Concept

Lease reader

A signed lease is read field by field, each one boxed on the page where it was found. Then the region’s rules turn it into dates.

Demo

A signed lease, dropped in as a PDF. Press play, or read it yourself.

The agency, the people, the flat and the lease are invented. The rules are paraphrased for the demo and are not legal advice. Nothing is sent or stored.

The other screens

Four more screens of the same tool.

The portfolio, the deadline calendar, one indexation and one unit’s file. Stills, with invented data.
  1. Demo Lettings
    Portfolio48
    New leases1
    Deadlines6
    Indexation3
    Rules by region
    Flanders
    Brussels
    Wallonia
    Sofie VoorbeeldProperty manager
    Demo LettingsPortfolio
    Find a unit, tenant or owner/
    Add leases
    AllNeeds actionFlandersBrussels
    FilterExport
    UnitRegionLease startRegisteredDeposit proofEPCNext indexation
    Voorbeeldlaan 12 bus 3GentFlanders1 Oct 2026Due 18 NovReceivedC1 Oct 2027
    Kerkpad 4GentFlanders1 Dec 2019 14 Dec 2019ReceivedB1 Dec · in 20 days
    Proefstraat 22 bus 1GentFlanders1 Mar 2024 20 Feb 2024MissingD1 Mar 2027
    Rue de l’Exemple 8BrusselBrussels15 Jun 2025 2 Jul 2025ReceivedE15 Jun 2027
    Testlaan 9AntwerpenFlanders1 Nov 2026 5 Nov 2026RequestedC1 Nov 2027
    Place du Modèle 2NamurWallonia1 Feb 2022 3 Feb 2022ReceivedNone on file1 Feb 2027
    Schetsweg 5LeuvenFlanders1 Sep 2023 29 Aug 2023ReceivedA1 Sep 2027
    Ontwerpstraat 31GentFlanders15 Jan 2021 2 Feb 2021ReceivedC15 Jan 2027
    Modelstraat 7 bus 2MechelenFlanders1 Jul 2022 11 Jul 2022ReceivedB1 Jul 2027
    Avenue du Croquis 14BrusselBrussels1 May 2024 16 May 2024ReceivedD1 May 2027
    Schetsweg 11LeuvenFlanders1 Apr 2025 3 Apr 2025ReceivedC1 Apr 2027

    Concept

    Portfolio

    Every unit with the state of its paperwork. The rows that need a person are marked; nothing about the tenants is scored.

    1 / 4
  2. Demo Lettings
    Portfolio48
    New leases1
    Deadlines6
    Indexation3
    Rules by region
    Flanders
    Brussels
    Wallonia
    Sofie VoorbeeldProperty manager
    Demo LettingsDeadlines
    MonthList
    Subscribe
    November 2026
    1. 26
    2. 27
    3. 28
    4. 29
    5. 30
    6. 31
    7. 1
    8. 2
    9. 3Registered · Testlaan 9
    10. 4
    11. 5Deposit proof · Schetsweg 5
    12. 6
    13. 7
    14. 8
    15. 9
    16. 10
    17. 11
    18. 12
    19. 13
    20. 14
    21. 15
    22. 16Task · register Voorbeeldlaan 12
    23. 17
    24. 18Register · Voorbeeldlaan 12/3
    25. 19
    26. 20Deposit proof · Proefstraat 22/1
    27. 21
    28. 22
    29. 23
    30. 24
    31. 25
    32. 26Notice ends · Avenue du Croquis 14
    33. 27
    34. 28
    35. 29
    36. 30
    37. 1Index · Kerkpad 4Index · Testlaan 2
    38. 2
    39. 3
    40. 4
    41. 5
    42. 6

    Concept

    Deadline calendar

    Every date the leases produce, on one month. The next thirty days, soonest first.

    2 / 4
  3. Demo Lettings
    Portfolio48
    New leases1
    Deadlines6
    Indexation3
    Rules by region
    Flanders
    Brussels
    Wallonia
    Sofie VoorbeeldProperty manager
    IndexationKerkpad 4
    Allowed from 1 DecReview letter
    Can the rent be indexed?Flanders, 9-year lease
    • The lease is in writingSigned 22 Nov 2019
    • It is registered14 Dec 2019
    • The anniversary has come1 Dec 2026, in 20 days
    • The tenant is asked in writingDraft ready, not sent
    The sumIndex figures invented for the demo
    Rent at the start€980.00× index, month before the anniversary132.41÷ index, month before signing109.88New rent from 1 Dec 2026€1,180.94

    Up €200.94 a month from the rent at the start. The last indexation, a year ago, was to €1,152.30.

    Letter to the tenantDutch, as the lease
    AI draft · not sent

    Beste mevrouw Claes,

    Volgens artikel 4 van uw huurovereenkomst voor Kerkpad 4 wordt de huurprijs jaarlijks aangepast aan de gezondheidsindex.

    Vanaf 1 december 2026 bedraagt de huurprijs € 1.180,94 per maand. De berekening vindt u hieronder.

    € 980,00 × 132,41 ÷ 109,88 = € 1.180,94

    Met vriendelijke groeten,

    Sofie Voorbeeld, Demo Lettings

    Built from the lease and the index tableEdit

    Concept

    Indexation

    Whether the rent may be indexed yet, the sum written out, and the letter drafted for a person to send.

    3 / 4
  4. Demo Lettings
    Portfolio48
    New leases1
    Deadlines6
    Indexation3
    Rules by region
    Flanders
    Brussels
    Wallonia
    Sofie VoorbeeldProperty manager
    PortfolioVoorbeeldlaan 12 bus 3
    1 deadline this weekEdit unit
    Register the lease by Wednesday 18 November. Sofie has the task, due Monday.Open task
    The unit
    Region
    Flanders
    Type
    Flat, 2 bedrooms
    Owner
    Voorbeeld Vastgoed BV
    Tenants
    Jonas Peeters, Ines Maes
    Rent
    €1,150 a month
    Lease
    9 years, from 1 Oct 2026
    Paperwork5 of 6 in the file
    • Lease, 4 pagesRead 11 Nov · checked by Sofie
    • Registration certificateMissing · due 18 Nov
    • Deposit, blocked accountProof received 25 Sep
    • EPC certificateLabel C · valid to 2033
    • Move-in inventorySigned by both, 1 Oct
    • Tenant’s fire insuranceRequested 2 Oct
    History
    1. 11 Nov

      Lease read; signing date checked by Sofie

    2. 2 Oct

      Insurance proof requested

    3. 1 Oct

      Keys handed over, inventory signed

    4. 25 Sep

      Deposit proof received

    5. 18 Sep

      Lease signed

    Dates from this leaseNext 3 of 5
    WhenWhatWho or where fromState
    Mon 16 Nov 2026Task: register the leaseSofieDue in 5 days
    Wed 18 Nov 2026Registration deadlineFrom the signing dateIn 7 days
    Fri 1 Oct 2027First indexation allowedSofieLetter due 1 Sep

    Concept

    Unit file

    One flat: its facts, the six documents it should have, and what happened when.

    4 / 4

What it would be worth

Missed deadlines become a list.

Every date the law hangs on a lease, on one calendar, with the close ones in red. The saving is the fine you never pay and the rent you remember to index.

€500–5,000

is the fine in Flanders for renting out a home without a valid energy certificate.

Source: Vlaanderen.be (opens in a new tab). The EPC when you sell or rent out a home, read on 11 Nov 2026. The law, paraphrased by me. It is not a result of mine, and whether a fine applies to a given lease is a question for your own advisor.

The other half is yours to count: for each lease nobody indexed on time, the index rise times a year’s rent. Count last year’s before anyone quotes you a saving.

What you can buy today

List prices as each vendor’s own page showed them on 11 Nov 2026. Both are full property suites. A custom reader is the better buy when your leases, regions and templates are the hard part, and you want the dates in the system you already run.

Rent you did not index, in euros

Count last year’s, from your own files.

Type your numbers and the sum appears here.

This is rent the leases allowed and nobody asked for. Whether it can still be asked for later is a legal question for your own advisor. Your numbers stay in this tab.

Where the line is

It reads paper. A person decides.

What it does

  • Reads a signed lease and finds the parties, the unit, the dates, the rent, the deposit and the EPC label, each tied to the words it came from.
  • Keeps what it is unsure of, like a handwritten date, amber until a person checks it.
  • Checks the lease against the rules of its region and turns them into dates.
  • Puts every date on one calendar and makes the close ones a task for a named person.
  • Drafts the indexation letter for a person to read, change and send.

What it never does

  • Score, rank or judge a tenant. It reads leases, not people.
  • Register a lease, send a letter or ask for money on its own.
  • Decide what the law says about a lease that does not fit the pattern. It flags it for a person.
  • Show a deadline that rests on a guess without saying so.

The rules belong to the agency and its legal advisor. The tool applies the ones they wrote down and shows the source of each. It is workflow software, not legal advice, and I would not present it as either.

Want this for real?

I would start with a week on twenty of your own leases: what they hold, which regions’ rules you need, and where your dates live today. Then a fixed price.

I would scope it as an internal tool: from €18k, usually 3–5 weeks, at a fixed price.

How I build internal tools