If a court remands someone into custody while pre-sentence reports are completed, that's a clear sign that only a custodial sentence is being considered.
If (as seems obvious from your post) you've been bailed, then it simply means that all options are being left open to the court.
Probation service staff aren't fools but giving them the answers 'that they're looking for', when they prepare your report, may substantially increase your chance of a recommendation in favour of a non-custodial sentence. So seeming remorseful is a good start! Then try to indicate that you're worried about the effect that possible imprisonment might have on other people, rather than on yourself. (If you've got children, or a partner who will suffer because of the loss of your income, mention them. If you've got frail, elderly relatives who you visit, or help to care for, refer to them). Make it clear that you regret your actions, regarding them a foolish, and that you'd comply fully with any community service order or supervision order made against you.
Courts usually try to keep people out of prison wherever possible but £42,000 is a fairly large amount. If you defrauded a local social club, causing it to close and its members to lose money, then you'd almost certainly be going to prison. But if you've simply lied on a mortgage application you stand a much better chance of avoiding custody.
Chris