Nuke, sorry I was in meeting 🙂 when I replied and edited twice.
To clear it up, if you are applying for an internal CS vacancy at the same grade (i.e not an pubic vacancy) the probability is that if you pay in your current department is higher than the minimum of the department that you are moving to, then that will be honoured.
The only reason I say probably, is because I’ve not know of an instance when that hasn’t been the case in 13 years of service, but I’m not an HR expert.
Regarding your A/L entitlement, you are still classed as being ‘continually employed’ so your time served should be carried across.
The most important thing is whether you really want to laterally move to an OGD. Yes, pay may be higher, but that’s a bit of a short term view, unless you have minimal experience in your home department already, or have a real desire to work in the new department.
There is a lot to be said for knowing the department you work for when sticking you head up for opportunities, but also helps you develop an understanding of the particular part of the public you work for & what they need (and therefore help you in your day to day decision making of what works/doesn’t work) I’m a big believer in the public servant thing 🙂
Some terms can be negotiable (excess fares etc) and you can get clarity on everything else from the vacancy holder, or their HR, after you’re offered a post.
Good luck whatever you decide.