Proof of work, signed on site

Get every job signed off before you leave site.

1 Sign replaces paper job sheets for installers, service and repair engineers — on the phone they already carry.

Customer signs on the engineer's phone or tablet
Before & after photos, date-verified on the job
Branded PDF certificate emailed in seconds
Works with no signal — uploads itself later
Your own paper forms, rebuilt digitally

Start your free 7-day demo See how it works

No card required · Set up in minutes · iPhone, Android & tablet · See a sample certificate

Everything you need to prove the job is done

Capture the details, get the customer's signature, and have a professional record in their inbox before you've left site.

Before & after photo proof

Engineers snap the job before they start and after they finish. 1 Sign checks the photos were taken during the job and embeds them in the certificate.

See photo proof

Works with no signal

Plant room, basement, rural site — the whole sign-off saves on the device and uploads itself the moment a connection comes back.

How offline works

Your own forms, digitised

Rebuild your paper sign-off sheets in the visual form builder, or start from the ready-made library. Included on every paid plan.

Build your forms

Capture signatures

Customers sign with a finger or stylus, right on the engineer's phone or tablet — no app for them to install.

Capture a signature

Branded PDF certificates

Every sign-off becomes a tidy, professional PDF with your company logo and details, saved to your control panel.

Brand your PDFs

Manage your engineers

Add engineers from your control panel — each gets a secure login of their own, and leavers are locked out instantly.

Add your team

Also on every plan Instant email delivery Private & secure Mobile-first, no app store Save drafts for multi-visit jobs

Start your free 7-day demo

No card required · set up in minutes

No signal? No problem

Keep working with no signal

Plant rooms, basements, rural farms, half-built sites — the places your engineers work are exactly the places with no bars on the phone. 1 Sign keeps going anyway: the whole sign-off is saved on the device and uploads itself the moment a connection comes back.

Saved on the deviceFill in the sheet, capture the signature and snap the photos with zero signal — nothing is lost.
Uploads automaticallyQueued sign-offs send themselves in the background the instant you're back online.
Installs like an appAdd 1 Sign to the home screen — full-screen on iPhone and Android, no app store needed.

Start your free 7-day demo How offline works

See 1 Sign in action

From the customer's signature to a certificate in their inbox — here's what it looks like.

Before & after photos — proof you can't argue with

Engineers snap the job before they start and after they finish, right in the sign-off. 1 Sign checks the photos were taken during the job — no old camera-roll shots — and embeds them in the signed certificate.

Why photo proof matters

A customer signing a job off on a tablet at the work site

Signed on the doorstep

The engineer completes the job sheet on their phone or tablet, then hands it to the customer to sign — a real signature, captured on site, the moment the work is finished.

Capture a signature

A branded PDF job completion certificate with signature, sent by email

A branded certificate, delivered instantly

Every sign-off becomes a professional PDF certificate carrying your company logo and details, emailed straight to your customer — before the engineer has left site.

See a sample certificate (PDF) Brand your PDFs

The 1 Sign control panel showing engineers and completed sign-offs

Everything in one control panel

Manage your engineers, watch sign-offs arrive in real time, and search or re-download any certificate whenever you need it. Your records, safe and in one place.

Set up your panel