Asked to do overtime at short notice

[CalmEddie]

Overtime is an employment concept. If you are outside IR35, wouldn't touch that with a bargepole.
10 mins. I'd do for free. If you get bent out of shape over 10 mins there's something toxic in the relationship and I'd be looking to move on. I certainly wouldn't rape the client for a full day.

But up to you. Be careful though, if you establish tacit terms that any part of a day equals a full day it goes both ways. This is business, not employment.

[PerfectStorm]

My work/personal laptop are the same and I have teams on my phone/laptop. Rookie mistake on my part

Nothing to stop you from closing the app.

Also - billing a day for 10 mins work out of schedule? I think that's going to cause you more problems. I'd take it on the chin if a one off (contractors should understand the concept of give and take) and maybe bill a quarter day if it becomes regular/planned/expected, or leave early one day to make up.

[PerfectStorm]

Overtime is an employment concept. If you are outside IR35, wouldn't touch that with a bargepole.
10 mins. I'd do for free. If you get bent out of shape over 10 mins there's something toxic in the relationship and I'd be looking to move on. I certainly wouldn't rape the client for a full day.

But up to you. Be careful though, if you establish tacit terms that any part of a day equals a full day it goes both ways. This is business, not employment.

Indeed to all of this. You're setting up an expectation that every single day you bill for is going to be ultimately accounted for it balls to the wall work. I wouldn't want that for the sake of 10 mins free work.

[d000hg]

If you had to go in to the office for 10mins, billing day-rate seems reasonable unless you agree something adhoc, to do so WFH I would struggle with unless the client made it very clear they don't care/the value of getting it done makes it worth a day's rate.

Stipulating working hours and out of hours rates in a schedule seems quite reasonable if it's you dictating it - I have a clause that I bill a full day if I have to visit the end customer's site.