How to Prove Unreasonable Behaviour

Last updated on May 24, 2018

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Divorce by Showing Unreasonable Behaviour

In order to get a divorce under Singapore law, one of the two spouses must prove that there has been an irretrievable breakdown of the marriage such that the two spouses cannot be expected to continue to live with each other.

One way to prove this, under section 95(3)(b) of the Women’s Charter, is by showing that the other spouse has behaved such that it would be unreasonable to expect the two married persons to live together.

What Exactly is Unreasonable Behaviour?

“Unreasonable behaviour” has a very wide meaning, and has been held to include any act, active or passive, or failure to act, of the other spouse. It has been found in a variety of situations from domestic violence to cases involving less serious complaints that, although not unreasonable as individual complaints, were cumulatively taken to indicate unreasonable behaviour.

Other instances include a case involving one spouse refusing to have conjugal relations with the aggrieved spouse for a period of over 10 years, and another in which one spouse constantly belittled the aggrieved spouse.

The central question here is whether the aggrieved spouse can be reasonably expected to continue living with the other spouse. The court will take into account both spouses’ character, attitude, and other attributes and the way in which they had acted throughout the duration of marriage.

Insufficient Instances of Showing Unreasonable Behaviour 

To show unreasonable behaviour, it is not enough that the parties are merely incompatible.  As was ruled in the case of Wong Siew Boey v Lee Boon Fatt, it is not sufficient “that [the parties] no longer have anything in common and cannot communicate or that one of them is bored with the marriage.”

It must go beyond a mere state of affairs or state of mind. For example, a feeling that one party’s love is not being reciprocated would be unlikely to be a valid basis.

The Test for Unreasonable Behaviour

The steps that the court will take in deciding on whether there has been unreasonable behaviour were laid out in the case of Castello Anna Paula Costa Fusillier v Lobo Carlos Manuel Rosado. The court will first look at whether the spouse seeking divorce finds it intolerable to live with the other spouse; this analysis is subjective thus it is irrelevant whether the aggrieved spouse had reasonable cause for his or her attitude.

The court will then look at the behaviour of the other spouse, taking into account any active or passive acts, to determine whether it is unreasonable for the aggrieved spouse to continue to live with the other. These acts must, of course, affect the marriage in some manner, but can include behaviour towards other family members and outsiders.  

While it does matter whether the conduct was malicious, it is not necessary to show malice to prove unreasonable behaviour.

The court will also look at the cumulative effect of the behaviour, i.e. whether there has been such behaviour for a long period of time. This means that a series of acts over a significant period of time that, while taken individually may not seem serious or unreasonable, when viewed as a whole may be found to be unreasonable.

For example in the case of Wong Siew Boey v Lee Boon Fatt, the aggrieved spouse had 23 paragraphs of complaints which, individually, may have seemed like the ordinary wear and tear of family life but when taken together was found to be a relevant factor in finding that there was unreasonable behaviour.

A determination in favour of divorce or against divorce does not necessarily mean that the offending spouse is guilty of any misconduct; the verdict only pertains to the marriage and whether or not the court finds that it may reasonably be expected to continue. The focus here is on whether the acts make it unreasonable to expect the couple to continue living together.


As there is no bright-line test to determine whether or not a particular situation would fall under “unreasonable behaviour”, we would recommend the aggrieved spouse to seek an experienced family lawyer who can provide legal advice on the matter.

Should you require any guidance on the costs of engaging a divorce lawyer in Singapore, please refer to our divorce fee guide.

Before getting a divorce
  1. Process for Getting Divorced in Singapore (With Diagram)
  2. How Can I Divorce Overseas?
  3. Mandatory Parenting Programme Guide for Divorcing Parents
  4. Online Divorce in Singapore: How It Works and Should You Get One?
  5. Getting a Divorce Due to “Irreconcilable Differences” in Singapore
  6. Judicial or Legal Separation in Singapore: When and How to File
  7. Should You Make a Post-Nuptial Agreement in Singapore?
  8. How to Divorce Within 3 Years of Marriage in Singapore
  9. Guide to Personal Protection Orders in Singapore
  10. Prenuptial Agreements in Singapore
  11. What are the Legal Grounds for Getting a Divorce?
  12. Separation in Singapore
  13. Annulling a Singapore Marriage: Requirements and Process
  14. Practical Preparations for a Divorce
  15. 3 Finance Questions To Ask Before a Divorce
Divorce Fees
  1. Comprehensive Guide to Divorce Fees in Singapore
Getting a Divorce Lawyer
  1. The Complete Guide to Choosing a Good Divorce Lawyer in Singapore
  2. First Meeting with Your Divorce Lawyer: What to Bring
  3. Don’t Just Go for the Cheapest Divorce Lawyer in Singapore
  4. Find Experienced Divorce Lawyers in Singapore
  5. Child Custody Lawyers in Singapore
Proving Irretrievable Breakdown of Marriage
  1. How to Prove Adultery for Divorce Purposes in Singapore
  2. Getting a Divorce: How to Prove Desertion
  3. How to Prove Unreasonable Behaviour
  4. How to Prove Separation for a Singapore Divorce
Application for Divorce Part I: Dissolution of Marriage
  1. Procedure for Dissolution of Marriage
  2. Divorce Mediation in Singapore
  3. Divorce Application: What to Do If Your Spouse Cannot be Found
  4. Simplified Uncontested Divorce vs Contested Divorce in Singapore
Application for Divorce Part 2: Ancillary Matters (Maintenance, Assets, Custody)
  1. Procedure for Ancillary Matters
  2. What Happens to Gifts Between Spouses During a Divorce?
  3. What Happens to Property and Assets Located Overseas Upon a Divorce in Singapore?
  4. Getting Divorced: Child Maintenance in Singapore
  5. Singapore Divorcee's Guide to Relocating Your Child Overseas
  6. Filling in a Matrimonial Property Plan for a Singapore Divorce
  7. Maintenance of Spouse in a Singapore Divorce
  8. Guide to Child Custody, Care and Control, and Access in Singapore
  9. How the Court Divides Matrimonial Assets in a Singapore Divorce
  1. What Happens to Your HDB Flat after Divorce?
  2. Variation of Maintenance Orders in Singapore
  3. Division of CPF Assets (Monies, House, Investments) After a Divorce
  4. Divorce Certs in Singapore: How to Get a Copy and Other FAQs
  5. Transfer of Matrimonial Home to Ex-Spouse After Divorce
  6. How to Appeal Your Divorce Case in Singapore
  7. Can Divorcees Buy or Rent HDB Flats, and How?
  8. What to Do If Your Ex-Spouse Denies You Access to Your Child
  9. What to Do If Your Ex-Spouse Does Not Provide Maintenance
Expatriate Divorce
  1. Can Foreigners Divorce in Singapore?
  2. Expat or Foreigner Divorce in Singapore: 10 Legal Issues to Consider
  3. Should British Expats Divorce in Singapore or England?
  4. Divorce for British Expats: How the English Courts Deal with Financial Matters
  5. Immigration Issues for Divorcing Expatriates
  6. Hague Convention: Overseas Child Abduction in Singapore Divorce
  7. Case Study: Cross-Border Child Custody and the Hague Convention on International Child Abduction
Muslim or Syariah Divorce
  1. Muslim Divorce in Singapore
  2. Applying for Nafkah Idaah and Mutaah in a Muslim Divorce in Singapore
  3. Talak in a Muslim Divorce in Singapore (and Its Effects)
  4. Guide to Divorcing by Khuluk for Muslim Wives in Singapore
Other divorce matters
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