A better way to say "as soon as possible"
KeepReap Editorial
"As soon as possible" fails for a practical reason more than a social one: it does not say when. The reader has to guess your urgency against everything else on their desk, and they will usually guess low. Replacing it with an actual time — and, where you can, the reason that time exists — gets faster replies than any softer phrasing.
Ways to say it
by Thursday, if possible
NeutralA2A real deadline plus a reason. "If possible" keeps it a request rather than an instruction without blurring the date.
ExampleCould you send the signed copy by Thursday, if possible? The vendor closes the quote on Friday.
at your earliest convenience
FormalB2Formal and common in external correspondence, though some readers find it stiff or faintly pressuring. Safe with institutions, less so with colleagues.
ExamplePlease confirm the address at your earliest convenience so we can dispatch this week.
whenever you get a chance
CasualA2Genuinely low-priority requests only. If you use it for something you need this week, you will not get it this week.
ExampleWhenever you get a chance, could you glance at the wording in section 3?
When not to use this
Do not use any softener when the deadline is external and immovable. "Whenever you get a chance" on a filing that must be submitted by 17:00 is not politeness, it is a misdescription, and the person who misses it will reasonably feel misled. State the hard time and the consequence, and be warm about everything else in the message instead.