Close company or make it dormant

[Maslins]

The issue is my year end is September, and my probationary period ends in December. I don't really want to pay another years accountancy fees, insurance fees etc on the off chance I need to use the company, hence my question about making the company dormant. I was under the impression from the gov.uk website and other accountancy / contracting sites that it was possible to make your company dormant once you had ceased trading and done a final set of accounts at year end, cancelled payroll etc.

"Making a company dormant" isn't really a thing. There's no one switch you/your accountant can flick that then means the company is dormant.

Always a bit tricky with these things as we on the forum don't know the full story and there might be significant relevant things not mentioned in your posts, but my view from what you've said would be:
- stick with your accountant, still paying the monthly fees, still submitting payrolls (albeit probably £nil), still submitting VAT returns (again will have naff all on them), until your probationary period ends. This just means if you did leave the PAYE role and want to revert to contracting, you've got a vehicle ready and waiting, which can easily put you back onto the payroll, is already VAT registered etc.
- assuming there is no company income after 1 Oct 19, you shouldn't need to do a set of accounts or CT return for a period after 30 Sep 19.
- if the PAYE role does work out well, your accountant should be able to do accounts/CT for year ended 30 Sep 19, potentially accruing for the modest costs (eg their fees, bit of insurance etc) incurred afterwards. Perhaps these be done in January once you're confident you're sticking with the day job.
- you then settle the final CT liability, and tidy up any other balance sheet items as appropriate, and look to close the company (prob via cheap and cheerful DS01 if final net assets will be sub £25k).