Undated Issue

When your kid just shows no interest in romance. One type of undated issue.

Another kind has to do with government debt. Most debt comes with a maturity date. You buy a 30-year Treasury bond with a 7% interest rate. That bond matures in 30 years. At that point, the government has paid back the money you lent it, plus all the interest owed.

An undated issue has no date. It's essentially a forever bond. The government just keeps paying you the interest, but never pays back the principle. The government can redeem the bonds if it wants (pay it off in a chunk), but the purpose is to keep the regular debt service payments as cheap as possible.

Undated issues are pretty rare, historically. The most famous examples of these come from British history. They happened mostly in the 19th Century and early 20th Century. The last outstanding undated issues were redeemed by the UK government in 2015.