An email that arrives already sorted.
Your address, and optionally the subject line and the first sentence. The message opens on their phone with all of it filled in, so what lands in your inbox is already labelled with where they scanned it.
More style options
Light grounds only — the code has to stay darker than what it sits on.
Six looks, made for paperwork and doors.
Pick one and it fills in the generator above. Job sheet and Reception desk are the two most at home on printed paper.
Where these earn their keep
Support and returns
A subject line of your choosing means every enquiry from the packaging slip arrives saying so. Filtering that is a rule, not a job.
Property and equipment
A code by the meter, the boiler or the lift, each with its own subject line. The email tells you which one before you open it.
Events and recruitment
A stand, a poster, a job ad — each with its own subject. You find out which one worked without asking anybody where they heard about you.
Questions people ask
Will the subject and message really be filled in?
In every mail app in normal use, yes. They travel as part of the address the code carries, the way a mailto link on a web page does, and phones have handled that for years. The worst case anywhere is that the extras are dropped and the message opens addressed to you, which still does the job.
Can I prefill more than one recipient?
One address, on purpose. Multiple recipients on a printed code is how a mailing list ends up visible to everyone who scans a poster.
Do you see what I type?
No. Nothing you put into a code is stored or logged — not the address, not the subject, not the message. The privacy page says exactly what is kept, and it is shorter than this answer.