# Hand a certificate between the office and an engineer

Source: https://help.mucka.ai/gas-certs/hand-a-certificate-between-the-office-and-an-engineer
Category: Certificates
Last updated: 2026-11-08

> The office sends a draft to an engineer to sign, the engineer signs and sends it back for approval, and a certificate approved by mistake can be re-opened before anyone's been sent it.

A lot of certificates are worked by two people: the engineer on site, and the office. Mucka lets you pass a draft between you, and always knows whose move it is.

By default the owner and managers approve certificates and engineers fill them in and sign. You can change who approves in [**Settings → Roles**](/settings/team/roles).

## The office sends one to an engineer to sign

Open the draft and tap **Send to sign**. Pick the engineer (it starts on whoever's named on it) and tap **Send**.

- They get a notification on their phone.
- It sits at the top of their [**Certificates**](/gas-certs) under **Waiting for your signature**, and the job's Paperwork shows it as **To sign**.
- When they open it, a note at the top says who sent it and when.

If you pick a different engineer from the one named, the certificate goes into their name, and any signature already on it comes off. It wasn't theirs.

## The engineer sends it back to the office

An engineer who can't approve sees **Send to the office** where Approve would be, once everything's filled in and signed. Tap it and it goes into the office's **Waiting for approval** list at the top of Certificates. If someone in the office sent it to you, they get a notification too.

Whoever approves opens it from that list and taps **Approve** as usual.

## Why a signature sometimes comes off

Your signature on a certificate says you checked what's on it. So if somebody else changes the certificate after you've signed, Mucka takes your signature off. The form says **Changed since you signed** and who changed it, and the office can tap **Send to sign** to hand it straight back.

Your own changes don't do this. If you change something after signing, your signature stays, because you're the one approving it or sending it on.

## Re-open a certificate approved by mistake

Approved it too soon, and nobody's been sent it? Whoever approves certificates can open it and tap **Re-open as a draft**.

- It goes back to being a draft with the **same number**.
- The approval and the engineer's signature come off, and it goes to the engineer to sign again, with a notification.
- The PDF that was made goes, and the service reminder the approval raised goes too (one you typed in yourself stays). They come back when it's approved again.

Mucka won't re-open it, and tells you why, if:

- it's been **sent** to anyone (the customer has that copy, so use **Amend**);
- its **boiler registration** has been started;
- it was itself a **correction** of an earlier certificate, or a correction of it is already under way. Use **Amend**.

If an engineer approved it on their phone with no signal and the office re-opens it before the phone catches up, the phone's approval doesn't go through. The engineer sees *"The office re-opened this certificate"* and can pick it up again.

## Common gotchas

- **No Send to the office button.** It only shows once the certificate is complete and signed. Tap **To do** to see what's left.
- **No Approve button.** Your role doesn't approve certificates. Use **Send to the office**, or ask the owner to change your role.
- **No Re-open button.** It's only on an approved certificate that nobody's been sent, and only for people who approve. Use **Amend** for anything else.