E-signatures for security, access control and AV installers
The install goes in, and goes in well. The argument, ten months later, is about when the warranty clock started, whether the two extra readers on the back door were a variation or were “included”, and who on site agreed to either.
This work ends with paperwork signed in a corridor. The engineer has the commissioning sheet on a clipboard or a battered tablet, the client’s facilities manager signs somewhere near the bottom, somebody photographs it, and it goes into the handover pack with the as-fitted drawings and the O&M manual.
That holds up until there is money attached to the question, and on this kind of work there usually is. Three separate things hang off one signature: when the warranty and maintenance period started, which revision of the design was accepted, and what was agreed as extra while the van was still outside.
The four signatures that come back to bite you
- The client acceptance or commissioning certificate. Your warranty and your maintenance period both run from it. If the only record is a date somebody wrote in biro, the start date becomes whatever the client remembers — and it is never remembered in your favour.
- The variation agreed on site. “While you’re here, put a reader on the back door and move that camera off the soffit.” Two hours and a bit of cable, priced verbally in a car park. It gets queried at final account, not on the day.
- The handover pack itself. As-fitted drawings, O&M manual, IP schedule, admin credentials for the recorder. Handing it over matters, and so does showing which revision they received, and when.
- Remote access and system administration. You keep a route into the client’s NVR or door controller so you can support it. The written permission for that, and for who may view recorded footage, is a one-page form nobody can find two years later.
None of those are difficult to produce on the day. All of them are difficult to prove afterwards, and proving is a different job from producing. A photographed sheet shows a mark on a page: not when the mark was made, not whether that sheet is the version you issued, not whether anything changed after. Sent on WhatsApp it is worse again, a cropped and re-encoded copy with the metadata stripped out.
What sending it through Pixasign changes
The job keeps its shape. You send the certificate, the client’s facilities manager opens it on whatever phone is in his pocket, signs, and it comes straight back. No app to install, no account to create: he taps a link in an email. The link stays live for fourteen days, which covers the man who is only on site on Tuesdays.
What changes is what you are holding afterwards. Every signed PDF gets a cryptographic seal — a PAdES B-T signature, the standard set out in ETSI EN 319 142, using RSA-3072 with SHA-256 — and an RFC 3161 timestamp issued by DigiCert.
That second part is the one that settles a warranty date. A timestamp is worth nothing if the company being asked about the date is also the company issuing it. DigiCert is an independent, publicly trusted timestamp authority, and its attestation that your signature existed at that moment can be checked by the client or their insurer without coming through us.
Alongside the sealed PDF you get an evidence certificate: who signed, the address it went to, their IP and approximate location, the device, the timeline to the second, and SHA-256 fingerprints of the file before and after sealing. The events are hash-chained, each one locking in the one before. Alter a character of that history and every seal after it breaks.
| The question | Signed sheet, photographed | Sealed through Pixasign |
|---|---|---|
| When did the warranty start? | The date written on the sheet | A timestamp issued by DigiCert, not by you |
| Which drawing revision did they accept? | Whichever one was in the pack | A SHA-256 fingerprint of that exact file |
| Who authorised the extra readers? | Someone on site, name half legible | Name, email, IP, device, to the second |
| Has it been altered since? | No way to tell | The seal breaks if a single byte moves |
| Can the client’s insurer check it? | They have to take your word for it | Anyone can check it, free, without an account |
Checkable by the client, their insurer and your inspector — without us
A sealed PDF is an ordinary signed PDF; it opens in normal PDF software and the signature is inspectable there. We also run a free public checker: drop the file in and it tells you whether anything has changed since sealing. No account, no login — which is the point when the person asking is a loss adjuster or the client’s new facilities manager.
Download your sealed certificates and handover packs whenever you like. They keep working if you stop being a customer, because the proof sits inside the file rather than on our server. The files live on hardware in Nuremberg with encrypted backups in Reykjavík — nothing of yours sits in the United States. The detail is on our security page.
Flat pricing, because more than one person sends paperwork
Most e-signature tools charge per user, which is the wrong shape for an install business. The engineer needs a variation signed on site, the project manager sends the acceptance certificate, and whoever is covering the office on Friday sends the maintenance renewal. Per-seat pricing leaves you paying for all of them or sharing one login — and a shared login destroys the audit trail you bought the thing for, because every signature comes back attributed to the same account.
Pixasign is one flat monthly price with unlimited users. £29 a month for 50 documents, £59 for 200, £99 for 500, VAT included, so the figure you see is the figure that leaves the bank. Put every engineer on it. Your clients never pay and never need an account.
Seal one commissioning certificate
Seven days free, no card. Take a certificate from a job you are finishing this week, send it to the actual client, and look at the evidence certificate that comes back.
Start free trial UK-built by Pixacomms Ltd, Cardiff. Nothing hosted in the United States.Questions
Will an electronically signed acceptance certificate satisfy our certification body?
Electronic signatures are valid and enforceable for the vast majority of UK business documents, and a client acceptance or commissioning certificate is an ordinary commercial record. Inspectorate and certification schemes are a separate question from the law, though, and they set their own rules about the form of documentation they expect to see. Ask whoever handles your scheme compliance before you move a certificate across. That answer should come from them, not from a supplier, ours included.
The facilities manager is only on site one day a week. Does that break it?
No. Send it when the engineer finishes, and the link stays live for fourteen days. He can read and sign it from his own office, or from home, on whatever device he has to hand. You are no longer waiting for him and a clipboard to be in the same building at the same time.
Can an engineer get a variation signed on site, there and then?
Yes. Send the variation from the van, the client taps the link on their phone, signs, and the sealed PDF and its evidence certificate exist before you have packed the tools away. Nothing is installed on their phone and they never create an account.
What happens to our handover packs if we stop paying?
Nothing is deleted. The account goes read-only, so you can still open and download everything already signed, and sending pauses until you pick a plan again. Anything you have already downloaded keeps working on its own, because the seal and the timestamp do not depend on us being here.