Do you need a prenup to own property in a mixed marriage?

If you are a foreigner married to an Indonesian citizen, this is the single most important document you will sign in this country, and a very large number of couples do not know it exists until it is too late.

The mechanism

Indonesian marriage law treats assets acquired during a marriage as joint marital property by default. Both spouses hold an interest in them.

Separately, Indonesian land law reserves Hak Milik, freehold, to Indonesian citizens.

Put those together. An Indonesian citizen married to a foreigner acquires freehold during the marriage. Because marital property is jointly held, the foreign spouse has an interest in it. Because a foreigner cannot hold Hak Milik, that interest is impermissible.

The practical consequence is that the Indonesian spouse's ability to hold and deal with freehold acquired during the marriage is compromised. Land offices and notaries are alert to this, and transactions get refused.

This surprises couples because nothing about it is intuitive. Nobody did anything wrong. The rules simply interact badly.

What a prenuptial agreement does

A perjanjian pranikah separates the estates. Each spouse's assets remain their own, acquired before or during the marriage. There is no joint marital property, so no impermissible foreign interest arises, and the Indonesian spouse can hold freehold in their own right.

It is executed before a notary and registered with the civil registry. The registration matters — an unregistered agreement is much weaker against third parties.

You can still do it after the wedding

For a long time the agreement had to be made before marriage, which left many couples with no remedy.

The Constitutional Court decision 69/PUU-XIII/2015 changed that. A postnuptial agreement — *perjanjian pasca nikah* — is now possible, made during the marriage, separating the estates from that point.

It is not a perfect substitute. It operates from the point it is made and its effect on assets already acquired and on third parties who dealt with the couple before it is more complicated. But it is a genuine remedy and it is used constantly.

If you are already married and have no agreement, this is worth doing now rather than continuing to put it off.

What it does not do

It does not let a foreigner own Hak Milik. It keeps the Indonesian spouse's freehold clean. The foreign spouse still cannot hold freehold, and no document changes that.

It is not a divorce settlement. It determines whether property is separate or joint. How assets are divided on divorce is a related but distinct question, and the agreement affects it — which is worth understanding and discussing openly rather than discovering later.

It does not solve inheritance. A foreign spouse who inherits Hak Milik still faces the disposal rules. Handle inheritance separately, with an Indonesian will.

The conversation

This is an awkward document to raise, and the awkwardness causes real harm because couples avoid it.

The framing that works, and that happens to be accurate: this is not about distrust, it is about a legal incompatibility between two sets of rules that produces a bad outcome for the Indonesian spouse. Without it, they lose the ability to hold land in their own country. The agreement protects them at least as much as it protects the foreign partner.

What to do

Before marrying, make a prenuptial agreement before an Indonesian notary and register it with the civil registry.

If already married, make a postnuptial agreement. Take advice on how it interacts with assets already acquired.

Use a notary experienced with mixed marriages. The drafting has to work for both the land law and the marriage law, and a generic template does not.

Get a sworn translation, and understand exactly what you are signing.

Keep the registered agreement where both of you can reach it, along with the marriage certificate.

Deal with wills separately. The agreement sorts ownership during life. Inheritance is its own problem.