Many couples do not make any changes to their banking arrangements until financial negotiations are well advanced.
But if there is a risk that large sums may be drawn out - or if there is a risk that credit or charge cards may be used inappropriately - then it may be safer to take action to prevent this.
The danger is that if an account or credit card is suddenly frozen, solicitors may be involved immediately to ask for maintenance arrangements to be set up - perhaps through the courts. This may be an unforeseen and costly consequence.
Much depends on whether you can trust each other enough to leave things as they are. If you need to rearrange the accounts on separation we recommend that you try to agree those changes first. Think about mediation.