Nobody likes thinking about this, so almost nobody does until it's too late. The result: a lot of estates are much messier and more expensive than they needed to be. A short read now saves your family a very long month later.
Three different legal regimes.
Different parts of your financial life pass through different rules.
Your will governs assets you own outright: your home, your savings, your car, your possessions. Executor fees, master's fees, and estate duty (above R3.5m) apply. It can take six to eighteen months to wind up.
Life insurance policies pay directly to the nominated beneficiary. They don't go through the estate. They pay within weeks, not months, and they don't attract executor fees.
Retirement funds (pension, provident, RA) are governed by Section 37C, which overrides your will. The trustees of the fund decide who gets what, prioritising legal and financial dependents regardless of what your will says.
The practical consequences.
Make sure every policy has a current, specific beneficiary nomination. Review them after every big life event (marriage, divorce, new child). And understand that your retirement fund is not yours to will to whomever you choose. The fund trustees will find your dependents and prioritise them.
Make it easy for your family.
A single place where every policy, every account, every beneficiary is listed, is worth writing. Your family will need it within days. Without it, they're phoning call centres and sorting shoeboxes. With it, they're grieving instead.