New job - dilemma over when to tell my manager

[TheFinalGirl]

Today I provisionally accepted a new job. It will take up to 4 weeks before I get my formal offer - it requires a lot of security checks - but having worked for this employer before I have no reason to believe I will fail them. My formal notice period is also 4 weeks.

I will be waiting for confirmation before I resign, but I wondered what people's perspectives are on telling my manager earlier - ie. within the next few days.

Background: I work for a small organisation and given the sort of work that we do, my departure will be pretty disruptive. Our work is project-based and giving them more notice would allow them to plan - especially in terms of allowing me the space to get my current projects finished. Having someone leave in the middle of a project is hard to manage.

On the other hand, what if something does go wrong and the new job falls through? It's unlikely but could happen. If it did I would like to stay - I like my current organisation a lot and I know that I am valued by them. I'm worried that they could terminate my contract if they know I was set to leave. I am basing this worry on nothing but my own paranoia. They treat employees very well...But you never know.

So should I tell my manager prior to handing in my formal notice? Just to be clear, this would effectively be the difference between giving them 7-8 weeks notice, or 4. I anticipate if I did he would also want our director to know but I'm fine with that - we have a good working relationship. I know they would prefer to know in order to plan...Equally, I feel it's in my own self-interest to keep it quiet until the new job is formally confirmed.

Any advice would be very gratefully received, sorry it was so long!

[TickettyBoo]

If you truly have a great relationship with them perhaps say it is "likely" that you will be tendering your notice in a few weeks time so that they can start to plan for that scenario.

[Littleallovertheshop]

I seem to end up working 8 weeks of notice every time I move job. If I like my boss I let them know as I don't want them to get a reference request out of the blue. Once formal offer is made I formally resign.