I need to confirm a verbal instruction today
It was said on site this morning, the work starts tomorrow, and it has to be in writing before it isn't.
What's happening?
Verbal instructions have a half-life. Today everyone remembers the conversation the same way; in three months the instruction becomes a suggestion, the scope shrinks, and the person who gave it has moved to another job. The work meanwhile gets built, at your cost, on the strength of a conversation.
The confirmation is the whole discipline: what was instructed, by whom, when, what it affects - sent the same day, inviting correction, so that silence starts working for you instead of against you. Many contracts set out this exact procedure with a deadline attached; where yours does, following its form and timing is what makes the confirmation bite.
The template is the same-day version: filled in, in the right shape, before the memory starts moving.
The solution
In writing today, while everyone still agrees.
If you would rather it were done for you, Variation Issuing & Registers is the service that does it.