I keep being called into work over the weekend and want to know what a reasonable amount to ask for would be.
Contracted Hours 9-5.30 Monday - Friday + Occasional Weekends
(occasional weekends = by prior arrangement , upgrades ect)
I live 40 mins each way from work.
I would say mileage cost (at company expenses rates) + minimum 2hours pay at overtime rates sat 1.5x sun 2x, even if it is walk in flick a switch, then walk out, you wont be out of pocket .
This should than mean any stupid call outs aren’t needed and hopefully only genuine calls be received 
Mileage to and from place of work would be taxable. I would ask for time and a half from leaving the house to arriving home, minimum 2 hours.
If you can get mileage as well, its worth 40p per mile.
Ask for a standby payment for being available + overtime, say £200 per week just for being available 24x7 or whatever you have agreed.
1.5 x for evenings and weekends
2 x for sundays and bank holidays
I do standby duties all the time , we get 38% to be available and 1.5x for actual hours worked weekdays and Saturday before midday and 55% and 2x from then until midnight Sunday and bank holidays , however this is a very regular event . 1800-2400 or 2400-0600 twice a week and 2 x 12hr duty one weekend in 6
If we get called out when not on duty it is 4 hours at the going rate plus overtime for all hours from accepting the call till we get back home .
Guys with looser arrangements IE programmers or network guys tend to share the load and get smaller payments on a sliding scale, once in a month is single £20 payment plus overtime ,twice is £50 plus ,three times is £120 etc. makes them think twice and really compensates for the inconvenience caused .
Again, it’s a regular deal here.
My arrangements are £3/hr (£4.50/hr Sun/BH) for being on standby switching to 1.5x (2x Sun/BH) for the duration of a callout in 30min increments or if I’m not on standby then 1.5x (2x Sun/BH) for 3hr min then 30min increments from thereon in.
Used to be something like:
mon-fri £8 per 8hrs on call, sat was £12 per 8hrs and sun was £16 per 8hrs, so would work out at 16hrs per day mon - fri, 3 x 8hrs sat, 3 x 8hrs sun for a grand total of (£80 + £36 + £48) then if you got called out you got a payment of £25 per ‘incident’ out, didn’t matter how many times you were called out for that incident, but if something else happened you got another £25! Nice. Usually worked out at £250’ish per week.
Now in the NHS it’s just a % of your salary depending on how often you are on call. i.e. 1 in every 3 weeks is 20% base salary, 1 in 4-7 weeks is 15%, 1 in 8-12 is 10%.
Callout per week
Monday - Friday Coverage from 6pm - 8am - £30 per Day
Sat & Sun - Coverage 24h - £50 per day
Bank Holiday - £70 Per Day
So £250 per week for being on the rota whether called out or not.
Then:
Milage @ 40ppm if called into the office
Travelling time (1x Salary)
Minimum callout time 2hr, so if you answer a call for 5 mins you get 2hrs of pay.
callout between 18:00 & 00:00 you get 1.5x salary per hour
callout between 00:00 & 06:00 you get 1.5x salary per hour + Time In Lieu
hey try working for the company I do, did 3 years on call, over half of it 2 hour notice to roll, to anywhere in the world, for as long as it took, and for the grand sum or sod all. yay
but they paid your travel expenses :lol:
And you got a bloody good salary to begin with anyway 
We’re at a flat rate on my team of $100/wk. We’re on-call by phone, required to come into the office only if we can’t perform the work from where we are. Its very rare to not be able to complete the work from wherever you are though.
Unfortunately it means some weeks you get nothing and other weeks you get hit with a couple of calls every day. Our inbound teams get 5 hours of regular pay/wk + 1.5x pay for the duration of each call billed in 15 minute increments. They get the better deal most weeks.