Not because they are unlucky. Because they are the four two-digit totals the tradition asks you to stop and look at before you reduce them away.
Almost every number in numerology is reduced. A total of 27 becomes 9, a total of 41 becomes 5, and from that point on nobody asks how the digit was reached. That works well enough for most purposes, and it is why so many calculators do nothing else. But it throws information away, and four totals are held to be worth keeping.
Consider a 4. It can arrive as a plain 4, or as 13, or 31, or 40, or 22 — and 22 is normally kept unreduced as a master number, so it never becomes a 4 at all. Every route ends at the same digit and the tradition reads them differently. The same is true of 5 arriving through 14, of 7 arriving through 16, and of 1 arriving through 19. Reduce first and you cannot tell which road you came down.
So the check is simple: write out the running total before you reduce it, and see whether 13, 14, 16 or 19 appears anywhere on the way down. If it does, that position carries the debt. If it does not, it does not — and having none is not an achievement, in the same way that having one is not a sentence.
Where to look
The five positions that are checked
A debt is recorded when one of these five totals passes through 13, 14, 16 or 19 on its way to a single digit.
A lesson, not a verdict
Nothing in the classical framing treats these numbers as a penalty being served. They are described as a tendency that keeps presenting itself until it is worked with — closer to a recurring lesson in a subject you find hard than to a debt collector. People with none are not luckier, and people with three are not marked. If a reading leaves you feeling sentenced rather than informed, the reading is wrong, not you.
Nobody can remove one for a fee
You will find practitioners offering to clear, cancel or burn off a karmic debt for a payment, often with urgency attached. There is no basis for this anywhere in the tradition, which frames the number as something worked with across a life rather than something deleted. Changing the spelling of your name changes the name-derived totals, and nothing about the date-derived ones. Treat any fee to remove a number as what it is.
The system you pick changes the answer
Name-derived debts depend entirely on the letter values you use. Pythagorean and Chaldean assign different numbers to the same letters, so a name that totals 16 in one may total 12 in the other. Neither table is the correct one. Pick a system, calculate all the name positions in it, and stay there — mixing them to find a debt, or to avoid one, is how a reading stops meaning anything.
What the number cannot do
A karmic debt cannot predict an event, name a year, or explain a piece of bad luck after the fact. Its only content is the description in the table above, applied to one position in your chart. If you are looking at it to make sense of something painful, it may give you a useful frame, but it is not evidence about what happened or why.