Imagine a soldier heading to the battlefield who writes to his son: "If anything happens to me, everything I own is yours." He survives the war and lives another thirty two years without ever making another will. When he finally dies peacefully in old age, does his son inherit under that old letter? Or picture a husband and wife who set out their final wishes in one shared document. When the wife dies first, can that document be admitted as her will?

Both questions turn on two of the more unusual corners of succession law: conditional wills and joint wills. The Law of Succession Act is silent on both, but Kenyan courts continue to recognise them as part of the common-law inheritance the country received from England. 

A conditional will only takes effect if a specified event occurs, and the courts must work out whether that event was a motive for making the will or a genuine pre-condition for it to operate. A joint will, meanwhile, is a single document made by two or more people, yet it functions as separate wills for each of them. Neither is addressed in Kenya's statute book, and lawyers generally advise against both, for the same underlying reason: uncertainty.

Understanding how they work matters for anyone thinking seriously about testamentary freedom  and for anyone tempted to add a condition to their own will without realising what that might cost their heirs.

Conditional wills

A conditional will takes effect only if a specified event occurs. If the event never happens, the will is void, and the testator is treated as having died intestate  as though no will existed at all. A person about to set off on a dangerous journey, for instance, might write: "This will shall only take effect if I die during this expedition." If they return safely and die years later of natural causes, that will has no legal force whatsoever.

The difficulty for courts lies in telling apart two very different intentions behind similar wording. In the first, the event is simply the motive: the danger prompted the testator to make a will, but they meant it to apply on their death, whenever and however that occurred. 

In the second, the event is a pre-condition: the testator meant the will to apply only if that specific danger materialised, and if it didn't, the will was never meant to operate at all. Because the two readings can turn on a single word, English case law  which Kenyan courts still draw on  offers three useful illustrations.

The soldier's letter: Re Spratt's Goods 

An army officer serving in New Zealand's Maori War wrote a "privileged will" — a will exempt from the usual formalities because of the circumstances of active military service. In it, he left everything to his son "should anything happen" to him.

 He survived the war and lived another thirty-two years without revoking or replacing the letter. The court admitted the will to probate, holding that "should anything happen" described the officer's motive for writing at that moment, not a condition on which the gift depended. The son inherited the full estate.

Motive or pre-condition? 

Whether a clause is a motive or a condition is not fixed by any formula; it is a matter of construing the testator's actual words against the surrounding circumstances. Courts ask, in effect, whether the testator meant "I am writing now because I face danger, but I want this to apply whenever I die," or whether they meant "this applies only if that particular danger kills me."

Where this leaves conditional wills in Kenya

Section 5 of the Law of Succession Act gives every person of sound mind, who is not a minor, the freedom to dispose of their property by will, but it says nothing specific about conditions attached to that disposition. In practice, conditional wills are rare in Kenya, and most practitioners advise against them. If a court reads an ambiguous condition differently from what the testator intended, the estate can end up distributed under intestacy rules that bear little resemblance to the testator's actual wishes. 

Anyone still set on a conditional will should state their intention in terms that leave no room for argument, saying explicitly whether the stated event is a condition the will depends on, or simply the reason they chose to write a will at that particular time.

Joint wills

A joint will is a single document in which two or more people typically spouses, set out their testamentary wishes together. Despite the shared document, the law treats a joint will as two separate wills, not one will belonging to both people jointly.

How it plays out on death

If a wife dies first, the joint document is admitted to probate as her will alone, and her husband's portion stays dormant. When he later dies, the very same document goes to probate again, this time as his will. One physical instrument ends up serving as two separate testamentary acts, executed together but taking effect at different times.

Why lawyers advise against them

The Law of Succession Act neither prohibits nor expressly provides for joint wills, and Kenyan courts accept them as valid provided they meet the formalities in Section 11 signed by the testator, or by someone else in their presence and at their direction, and witnessed and attested by two or more competent witnesses. Even so, most practitioners steer clients away from joint wills, largely because changing one's mind gets complicated: since both people's wishes sit in one document, one party altering their share may require the other's consent, or force a full revocation and fresh start. 

Attribution can also become unclear, since a poorly drafted joint will can leave it genuinely uncertain which provisions belong to which testator. And circumstances change after the first death. A surviving spouse who wants to remarry or revise their estate plan may feel, rightly or wrongly, bound by terms agreed jointly years earlier. Separate wills, cross-referenced where useful, generally achieve the same goals without these complications. 

Where a joint will is presented for probate after one maker's death, courts treat it as that person's will alone, and expect the document to make clear which provisions are whose.

The bottom line

For most people, the safest path remains a straightforward, properly executed will, free of conditions and shared authorship. Anyone drawn to a conditional will should spell out, in unambiguous language, whether the stated event must occur before the will operates. 

Anyone drawn to a joint will should weigh whether separate wills  simpler, more flexible, and easier to amend  would serve them just as well, and if not, ensure the document clearly separates each party's wishes.

Conditional and joint wills are genuine, if uncommon, features of Kenyan succession law. They illustrate how far testamentary freedom can stretch to accommodate unusual circumstances. But for nearly everyone, they remain more interesting as legal curiosities than as practical planning tools. As practitioners often put it: keep your will simple, keep it clear, and keep it unconditional.

This column is for informational purposes only and does not constitute legal advice. Consult a qualified professional for guidance specific to your circumstances.