Backwards Posting

One possibility is that as you are highlighting (or ticking and bopping) the numbers that match, one of the numbers is the same as on the other list, just the wrong way. For example, you may have a debit in List A of 1,240 and a credit in List B of 1,240 that you have inadvertently matched off against each other.

To see if you may have made this type of error, take the amount that you are still out by and divide by 2. Then look for that number in your list. In the above example, an error like that would have made you out by 2,480. You would divide that number by two to get 1,240 and would have found that number in both lists. Once you took a better look at those numbers, you would have discovered that one was posted backwards, causing the out of balance.

Transposition Error

This is another common bookkeeping error. It occurs when two numbers are switched. For example, you may have wanted to write 57 but you wrote 75 instead.

Finding these errors is quite simple. They are always divisible by 9. In the above example, the difference between 57 and 75 is 18. Eighteen is divisible by 9.

You can also narrow down the magnitude of the error you are looking for. The difference above is 18. This tells you that the problem is in the tens column. If you made a transposition error by posting 8,312 instead of 3,812, the difference is 4,500, so you know the error is in the thousands column. This little trick can shorten your search time (and your annoyance level).

Addition Error

Many errors in adding are divisible by 10. For example, if the sum of three numbers is $475, you may have posted it as $465 or $485. There may be an addition error in the original posting or in the reconciliation itself. Check over your reconciliation first to see if you have an adding error there.