Letters in Membership Number

My LDS Membership Number, which I am sure is correct, ends in letters, not numbers. Example: ###-####-##DA. I am aware of 1-2 others in my ward with their MRN in this format, but we can find no commonalities. It has always been my number, and is not a re-issue or anything similar. Does anyone know the reason for this?

It's just part of the system. There is no significance or meaning to it. The last digit is what's called a "check digit". It exists to make sure the other digits have been entered correctly. That way, the system will likely spot a mis-entered number and not pull up someone else's record. It's pretty common practice. For example, credit card numbers work that way. Some bank account numbers may as well.

It just so happens that the mathematical combination of digits in your MRN come out to "10", so the letter "A" is used.

I don't have any answers, just guesses and a couple of counter-questions:

I was going to guess that increasing the numbers of symbols in each character position increases the number of possible MRNs. However, even with just digits, 11 characters gives around 100 billion (10^9) numbers, which (IIRC) is larger than the estimates I'm acquainted with of the total number of humans who have lived or are living on this planet. If increasing the size of the pool is the reason, it would likely be planning ahead for something significant.

Another guess is that it might be to increase the pool to reduce the rate of adjacent numbers that are valid, sort of an error-detecting thing. If that's the reason, it would reduce the rate that a membership clerk looking up a member by MRN would have a digit or two wrong and have a valid number for a different person. That is somewhat plausible but still just a guess.

Is it only the last two character positions that have letters? Or, are the letters scattered around the rest of the columns?

Are all the letters A, B, C, D, E, or F? If so, that would indicate hexadecimal encoding. If there are other letters, that would indicate a more complex encoding scheme.

The second to last digit should be a number. The last digit can be an "A" as was stated. My mrn ends with an A as well.

It's a check digit.

The second-to-last character in your MRN is a zero, not a D. The only non-digit value in an MRN is the A that appears in the check digit position.

I never thought much about this issue until today. Trying to get my wife set up through Gospel Living app and Circles, she gets a weird error message when she clicks on Circles. Investigating this with my Bishop, it seems she is probably the only member of our Ward getting this issue we know of, and the only one with an A instead of a digit at the end of her MRN.
Guess I’m calling SLC this week, since Circles is now the only way my Ward is communicating things with one another.

It is not unusual to have a letter at the end of a membership number. I have the letter A at the end of my own! Not hundred percent sure, but I believe this is part of the checksum. If I’m wrong in this, I’m sure someone will correct my assumption.

Biggles wrote: Sun Jan 28, 2024 4:19 pm I believe this is part of the checksum.

That is correct.

Check in Ward Directory and Maps. I think you can see your spouse's MRN. Make sure it matches what's on the account and that it's in the ward.

Also check to see if she has 2 factor authentication turned on. The mobile apps don't support all of the 2FA options.