How court fines work when in prison custody?

You have been very unfortunate here, Nash, as these fines could have been lodged while you were in prison. What I would do in your position is turn up at the Fines Enforcement court with full details of the amounts and the dates of your imprisonment and every other relevant detail and perhaps the magistrates will decide to write off your fines by ordering you to serve one notional day of imprisonment. Don't suggest this -- it is something they have to decide of their own accord. It's not something you can expect as your due, but it is a solution which suggests itself in these cirstances.