In general, your spouse is likely to have a claim to a share in any assets. This applies even if you have worked to build up your business while your spouse has been a 'homemaker': the courts may well decide that you each contributed equally (though in different ways).
Once divorce proceedings are underway, you are unlikely to be able to remove your spouse's claim to a share of the business. You may be able to negotiate an agreement where you retain, say, the business, but your spouse gets a correspondingly large share of other assets (such as the house or your pension fund).
If the business constitutes the majority of your assets, this approach becomes more difficult. You may be able to retain the business by borrowing to pay your spouse. Ultimately, you might be forced to split the business or to sell it to a third party. This may itself cause extra problems if you create a tax liability.
There are steps that may help to protect your business against the possibility of a divorce in future. Suitable terms in the shareholders' agreement may help, as might appropriate terms in a pre-nuptial agreement. However, in the event of a divorce, a pre-nuptial agreement might be overridden to reach a fair financial settlement. A more effective option may be to hold shares in trust, for the benefit of the family, rather than directly; you may be able to include this as part of a tax-planning exercise. This is a complex area where you will need to take advice.
