You may have seen a recent TV series covering wealthy divorcees and how some struggled to claim the kind of settlements they thought they deserved. Whether their claims were justified or not, the series highlighted how their former husbands had put lots of forward planning in place to make life difficult for their ex wives in there attempts at compensation for their contribution to the marriage.
One of the better known ways to protect your wealth in case of a future divorce is to sign a prenuptial agreement which places legally binding restrictions on what one partner is able to claim from the other in the event of a parting of ways.
The reality is most couples in the first throes of a romantic relationship are unlikely to consider such an agreement unless they happen to be particularly wealthy or they are some kind of celebrity where such agreements are commonplace.
So the main ways to protect your assets and cash is to put in place some degree of separation. For example you may want to separate your joint accounts from individual accounts and if you own property, then who owns it should also be clearly defined.
The example in the TV show saw husbands spiriting away their cash in offshore accounts and various other ways to hide what was alleged to be their true net worth. Most of us mere mortals are not going to have access to these types of devious schemes but keeping accurate records can also help particularly when it comes to assets left in wills and trusts.