There are some firms like Supermarkets that don’t like you “knocking off at the 8 hour mark” - because of that very bit where you work 8, should get deducted 45-60m for the break, but because of the “guaranteed paid 8” you don’t get it deducted!
I call the period 8hours to 9hours into a shift “Happy Hour” because it’s the hour you work for the firm for nothing…
You want to either go home prior to the start of “Happy Hour” - Or end up doing a shift significantly longer than 9 hours, to make it worth your while.
At places like Royal Mail where you get decucted a 90 minute meal break once you get to a 12 hour shift - you’ll quickly notice that the shifts available for agency to do are often 12.05, 12.15m and the like… The ones the full timers and parity pay contractors leave on the table because of that heavy deduction. (If you’re not on the parity pay contract, they’ve got no right to deduct you 90 mins at the agency of course… Make sure they don’t try it on regardless though!)
Who wants to continuously work 9 hours and get paid 8 all the time? 
Winseer:
There are some firms like Supermarkets that don’t like you “knocking off at the 8 hour mark” - because of that very bit where you work 8, should get deducted 45-60m for the break, but because of the “guaranteed paid 8” you don’t get it deducted!
I call the period 8hours to 9hours into a shift “Happy Hour” because it’s the hour you work for the firm for nothing…
You want to either go home prior to the start of “Happy Hour” - Or end up doing a shift significantly longer than 9 hours, to make it worth your while.
At places like Royal Mail where you get decucted a 90 minute meal break once you get to a 12 hour shift - you’ll quickly notice that the shifts available for agency to do are often 12.05, 12.15m and the like… The ones the full timers and parity pay contractors leave on the table because of that heavy deduction. (If you’re not on the parity pay contract, they’ve got no right to deduct you 90 mins at the agency of course… Make sure they don’t try it on regardless though!)
Who wants to continuously work 9 hours and get paid 8 all the time?
I didnt think that a company like RM would do that, I thought was a general haulage thing, to my thinking, if your not at base when a break is due, then you should be paid it.
At the only company I worked for that did this, it got silly one day when I was yard bound for the morning. So I get my pack up and join the fitters for dinner, bearing in mind it was unpaid, after about 5 mins TM walks in demanding I do a particlular run, like now. Not til I’ve had my dinner hour, which as pointed out to him would recommence from the start ei 60mins remaining, when he sodded off and left me in peace. Needles to say he’d give the run to some one else
I did leave not long after that, as I couldnt afford to keep cutting my own throat just to ■■■■ up the TM, but it was fun. Bit off a personality clash you see