Joint return even if spouse doesn't sign?

Filing a joint return is really an election. What happens if you sign the return but your spouse doesn't? The regulations and an old case have held that where the filing status on tax return indicated married filing joint return, but the taxpayer's wife did not sign the return, did not object to its filing, or did not file a separate return herself, it was presumed that the joint return was filed with the tacit consent of the wife. Returns signed by just one spouse will qualify as valid joint returns only if both spouses intend to file joint returns. The factors evidencing intent to file a joint return are: a lack of reason for a refusal to file a joint return, the absence of objections by the non-signing spouse, the delivery of tax data to one spouse for the purpose of making the tax return, and the apparent advantage in filing a joint return. While this can be a loophole if your spouse inadvertently fails to sign, the safest approach is to make sure both sign.