never underestimate how HR can over complicate things

It gives them something to do.

HR is a bucket of poisonous nonsense.  

If you followed the statutory procedure requesting flexible working in the first place to go to 4 days a week, when this was agreed it was a permanent variation to your terms and conditions of employment.

Your request to return to full-time working is therefore a further change to your terms and conditions of employment.  Your employer could simply document this without following a procedure, but likely have an automated system for managing flexible working applications and subsequent changes to terms and conditions, so funnelling you through that is easier than doing something bespoke.  

Looks like it is designed for people reducing their working hours/days rather than increasing them. 

I would have thought a better pitch would be to say that your increased working time would result in more work/income for the firm and more client satisfaction (etc) rather than less work for others. 

Yeah, I'm sure that your employer should just have welcomed you back with a slap on the back / quick pint and totally disregard: (i) any and all employees who were either covering the shortfall(s) and/or are now potentially redundant and/or are have (or could claim to have) a protected characteristic and have been (or could claim to have been) subjected to less favourable treatment over you because you've deigned after "the past few years" to finally max up your hours again (ii) any potential claim(s) that may arise therefrom; (iii) their published procedures in respect of the same; and (iv) the law.

AP when I original went part-time it was part of switching from a temp contract to a permanent contract so I was just issued a new contract with four day week.  We're old school and no automated system so a human has come up with this.

Kimmy it is indeed designed for people reducing hours which is why it has all been a bit backward.

Bright I'm part of a job share with a guy in his early 70's who's slowly winding down to retirement and reducing his hours further so nobody is going to be losing their job as a result of me working more and there's more than enough work to go round.  

Sails - I'm sure that guy wouldn't. The reason you have to go through the process is 'cos of the lots and lots of other people who were 'that guy' in previous scenarios where the employer thought as you/your employer did and then got shafted. It's sensible risk management from the employer's perspective.

What BC said.

What you think is common sense has often resulted in a 6 week discrimination Tribunal.

Human Remains being unhelpful as normal

But if that's the process, isn't it gonna be easy - trial isn't really a trial as you've been doing the job for years?? Just sign the paperwork and let Human Remains buys themselves with it for a while

**busy themselves

Fair enough BC but bear in mind I'd spent several months discussing it with my head of department and others and they could have taken into account others without me filling in a form that really wasn't applicable.  Couldn't they have considered things and made a note for the file that to that extent and just given me revised terms?

MM the trial is just part of the standard flexible working letter.  The only bit I want to check is the holiday entitlement as seems to be less than I had when I was full time.

Couldn't they have considered things and made a note for the file that to that extent and just given me revised terms?

This is fine as long as everyone is getting along.  Without the process, if you turn into a problem employee you may raise it wasn't done properly.

Well not YOU, because obviously YOU are reasonable and great.  THAT GUY would.  And everyone gets treated as THAT GUY.

Yes, Sails, they could have done, but that might have left them open to the 6-week discrimination tribunal that Alan Partridge referred to above, which is very probably why they didn't and asked you to fill a form in and do a trial period instead.

Plus wot Maid Marion sed - it's just standard nowadays 'cos too many have brought too easy claims before when people didn't bother taking easy steps to protect the business.

I am sure we have all got our stories but for me peak was a pushy and humourless young woman from HR  with whom I crossed paths with regularly (not in a bad way, but almost physically as our respective offices were literally next door to each other, on the same floor.) She was a fairly dour Continental (German but I think she was born in one of the Accession 8 EU states.)

A few years back we were notified of a compulsory day long equalities course which all staff needed to attend. We were given a choice of about 4 dates. However, I was so busy that I put off putting my name down. Perhaps I did but had to cancel due to work reasons. The day before the last course, she walked up to my desk, and without so much as a greeting, said "You have not been on the course, yet. You will have to attend the one tomorrow as it is the last one being held this year."

I tried to explain the reason why and told her "Anyway, I am due in court tomorrow on an application. But, as long as there is no hold up on the list, I should be back in the office shortly after midday so I can attend for the rest of the day." She replied "You have to attend the whole course. From the start." I replied "I understand, but you do realise that I have been on this same course about every two years for the last eight years? And your department actually seeks advice from me on internal employment matters including the application of equalities legislation and policies? I probably already know more about this stuff than anybody in the entire building."  

Abruptly she responded "You will attend the course." I got the impression she was alluding to the possibility of disciplinary action if I did not. 

I was getting fed up with this by this stage and told her "Oh ok, if at about 10.30 tomorrow morning I am in the middle of addressing the judge in the application, I will tell him "Sorry, My Lord, I have to go now as I have an HR course to attend". I think that went over her head. And she walked away.

As it turns out the application was met in response for a request for an adjournment, which was granted, so the hearing lasted about 10 minutes and as the office was quite close to the Court I was back well before 11am.