Let’s Seal

Seal and verify property & conveyancing documents

Tenancy agreements, leases, transfer deeds, and title documents that carry their own proof — so a tenant, buyer, lender, or agent can confirm a document is genuine and unaltered in seconds. A forged tenancy or an altered deed fails on sight.

For conveyancers, estate & letting agents, landlords, and developers.

Open the app Developer docs
What a seal proves

Four guarantees, in property & conveyancing

The agreement can't be doctored

A changed rent, term, name, or clause — one altered byte — fails verification. What was agreed is what verifies.

The issuing agent or firm, named

Every tenancy, lease, and deed names the agent or conveyancer that sealed it, chaining to a published root — a specific certificate, not a vague badge.

Fixed at the moment of issue

A Bitcoin timestamp pins when the document existed — decisive for start dates, completion, priority, and which version was signed.

Checked by anyone in the chain

A tenant, a lender, or the other side's solicitor confirms the document at a permalink — instantly, and free.

How it works

From your file to a proof anyone can check

The same pipeline every time — the seal and the timestamp travel with the file, so the proof is self-contained.

Your file
Your signed PDF
Seal
Signed over every byte · PAdES
Anchor
Bitcoin timestamp + public transparency log
Proof page
A permanent /d/… link travels with the file
Anyone verifies
Free, public, offline-capable — for anyone
The proof travels inside the file. Verification stands on the published root, the transparency log, and the Bitcoin ledger — so a court, a bank, or a counterparty can check it independently, forever.
Step by step · the web app

Seal it in the app — no setup

  1. 1

    Sign in as your agency or firm

    Open app.letsseal.org and sign in. Your organisation gets its own certificate authority the first time you seal — every document you issue chains to it.

  2. 2

    Upload the signed document

    Drop in the tenancy, lease, or deed. It's sealed with your certificate as a PAdES signature covering every byte, so any later edit is caught.

  3. 3

    Anchored and logged automatically

    The fingerprint is timestamped on Bitcoin and written to the public transparency log. You get back a normal PDF that also verifies.

  4. 4

    Send the proof link with the document

    Every sealed document has a permanent proof page. Give the tenant or buyer the link; anyone opens it to confirm the document is genuine and current.

Step by step · the CLI

Automate it from your terminal or CI

The sealbot CLI does the same thing, scriptably — one command per file, straight into your pipeline.

# Seal a tenancy agreement under your agency's certificate
$ sealbot seal tenancy-agreement.pdf --org examples
sealed   tenancy-agreement.pdf
  proof  https://letsseal.org/d/6c31af…b8e2
  anchored to Bitcoin · recorded in the transparency log

# Issue at volume: seal every agreement as it's finalised
$ sealbot watch /srv/tenancies --mode seal --org examples
watching /srv/tenancies … sealing new & changed PDFs (idempotent)

# A tenant or lender confirms it — public, no account
$ sealbot verify tenancy-agreement.pdf
✓ authentic · unaltered · sealed by Let's Seal Examples

Point a watched folder or your case-management system at Let's Seal and every agreement leaves already sealed, timestamped, and carrying a proof link — one command, no per-document fee.

Full CLI & API reference
See it in action

What a proof looks like, and what you can seal

Issuer verified — controls letsseal.org
Authentic & unaltered
Document
A sealed tenancy agreement
Issuer
Let’s Seal Examplesletsseal.org
SHA-256
64-hex fingerprint ✓

Anchored on Bitcoin

Recorded in the public transparency log

Public and free to verify — by anyone, with standard tools.
Open the live proof

A single use case, many documents. Each of these is sealed the same way:

  • A sealed tenancy agreement

    Live proof

    Open the proof page the way a tenant or lender would: it shows the agreement is authentic, unaltered since sealing, issued by the named agent, and timestamped on Bitcoin.

  • A lease or licence to occupy

    Commercial and residential leases sealed on execution, so a lender, guarantor, or incoming tenant can confirm the terms are exactly as granted.

  • A transfer deed or title document

    Seal the TR1 or title pack so the buyer's solicitor can verify the document is genuine and unaltered — an altered deed fails on sight.

  • A completion statement or inventory

    Financial statements and check-in inventories sealed and dated, so there's no dispute later about the figures or the condition recorded at the time.

Live proofs are real documents sealed under the “Let’s Seal Examples” organisation.

Common documents

What you’ll seal

  • Tenancy agreements
  • Leases
  • Transfer deeds (TR1)
  • Title documents
  • Inventories
  • Property searches
  • Completion statements
Questions

Straight answers

Does this replace signatures or witnessing?
No. A seal proves the document is authentic, unaltered, issued by you, and existed by a date. It's the cryptographic layer beneath whatever signing or witnessing the transaction requires — not a substitute for it.
Can a tenant or buyer verify without an account?
Yes. Verification is public and free — they open the proof link, or drop the PDF into the verifier. The proof carries everything they need.
What if the lease is varied later?
Seal the varied version too. Each version gets its own seal and timestamp, so the record shows exactly what was in force when — useful if a dispute turns on which version applied.
Can I seal a whole portfolio of agreements?
Yes. Point the CLI or a watched folder at your document store and every agreement leaves sealed, timestamped, and carrying a proof link — one command per document, no per-seal fee.

Start sealing property & conveyancing documents

Free and open. Seal in the app, automate from the CLI, and hand anyone a proof they can verify themselves.

Open the app All use cases