I just wanted to share my experience with Parasol. If you are thinking of using them, my one piece of advice to you is: don't. Find a different umbrella, or go Limited.
I did some work with them for a two month contract (or thereabouts) a few months ago, and inputted my time sheets correctly, weekly, as you are meant to.
Parasol claim that you'll get paid weekly but I found that this was a false promise. I didn't get paid weekly but I'm not sure if this was to do with them or another third party. Either way - I didn't get paid weekly regularly. It sometimes happened, sometimes didn't.
Anyway - I was putting in my time sheets weekly, and then one day towards the end of my contract, someone at Parasol's end logged into my account and merged all my weekly time sheets into two or three big chunks. I'm not sure what the logic was behind this - but it meant that I couldn't then differentiate between weeks, and the total pay became two or three larger sums (sorry, I can't fully remember how many chunks but I know they merged my separate weekly payments into larger chunks).
Because Parasol take a big chunk of your pay anyway, and also NI and tax, it's not the easiest calculation to make to determine what your total pay should be when it's all merged together (for no reason!). So they condensed my last few weeks into these bigger payments, and paid me all at once.
A month or two later, I had an email saying they had incorrectly paid me, and turns out they'd overpaid me by £600. Whoever had messed with my time sheets, had overlapped some and made an error which meant they'd mixed up some dates and ended up paying me twice.
As I had no record of my weekly invoices because they had amended what I'd put in, I had to go back and forth for ages trying to work out what was correct and what wasn't, but they're so cagey about what they take off, that it was quite confusing to try and work out the totals they should have been.
Lesson to me - obviously I should have tracked my days and invoices in my own record system, rather than relying on Parasol. I just had no idea that they would do this.
Anyway - when I was trying to work all this out, a couple of weeks later they changed their story and added on an extra £250 that I owed them, claiming they'd made a mistake. This does not make me think that they are trustworthy!
Anyway - long story short, I have to pay them £800 back because they overpaid me. Which I think is totally unacceptable due to it being no fault of my own. I'm new to freelancing, and when your pay varies so much from month to month, it's not hard to see how I didn't notice this - especially when they merge all your payments together - for no reason! Except maybe they knew what they were doing and just want to make some extra cash?! Who knows.
TL;DR - Parasol didn't pay me when they said they would, mucked up my timesheets and then cocked up my payments. Don't use Parasol.