For gas engineers

CP12s done on your phone.
Sent before you leave site.

CertBox lets gas engineers create professional certificates on any phone and share them instantly.

Your first certificate is free. Then £4.99 each, or £14.99 a month for as many as you like.

Sound familiar?

The paperwork side of gas work takes longer than it should.

Paperwork after the job

Writing up forms at the kitchen table after a full day on site. Then scanning, emailing, and hoping the landlord can read your writing.

Chasing signatures

Landlords who are never on site. Letting agents who want the certificate before they pay. Getting a signature takes longer than the job.

No signal on site

Basements, plant rooms, rural properties. Half the jobs you attend have poor or no mobile data at a critical moment.

Certificate on a phone

A blurry photo of a handwritten form sent via WhatsApp is not a certificate. Landlords and agents increasingly want something professional.

How it works

1

Open CertBox on your phone

Works in any phone browser. Add it to your home screen for an app-like experience. Sign up in under a minute.

2

Fill in the form on site

Captures signature on screen. Done before you leave.

3

Send the link instantly

Share a secure certificate link or PDF with the landlord or letting agent before you drive away.

CertBox certificate list showing a valid CP12 gas safety record

Built for gas engineers

Every feature designed around how gas engineers actually work.

CP12s in minutes

Fill in a gas safety record on your phone between jobs. Use "Create Similar" to copy address and appliance details for repeat landlord work.

153 certificate types across three countries

Gas safety records, service records, commissioning sheets, warning notices, and more. Everything a gas engineer needs in one place.

Instant sharing

Send a certificate link to the landlord or letting agent before you leave site. No scanning, no posting, no WhatsApp photos.

Frequently asked questions

Less paperwork. More jobs.

Create your first CP12 today. Your first certificate is free. Then £4.99 each, or £14.99 a month for as many as you like.