From a Companies House perspective, if your company is truly dormant, then it only incurs Companies House fees annually. In these circumstances, then you can submit dormant accounts which comprise a simpler Statement of Financial Position (formerly a Balance Sheet) and notes.
However, one of the main benefits of being dormant from a HMRC perspective, is that you are no longer required to submit a company tax return if your current accounting period does not have any taxable income. You do have to advise HMRC of this -and if you return to trading after a period of time, it is your responsibility to notify HMRC. If you don’t, then there are penalties for failure to notify HMRC that your company is now liable for corporation tax.