Unfortunately, I think these are your only options:

1. Use other software that is capable of handing more digits (and that software will likely be much more expensive).
2. Manually fill out the form via a PDF from the IRS website and either (a) attach it as a PDF to the e-filed tax return or (b) mail it with the rest of the tax return.

Thank you for your answer. It's very unfortunate. I guess need to look for other software. Any recommendation ?

I could be wrong, but I don't think there are many options for software that handles a large number of digits.

Perhaps someone that uses Lacerte knows how many digits it can use - that would be the easiest learning curve for you because Lacerte is extremely similar to PTO.

UltraTax MIGHT.  But I'm not sure.

I know that ProSystem fx does (and likely Axcess), but those are extremely expensive software options.

Thank you

Lacerte has the same limitation on number of digits. You can type in up to 13 digits, but you get a "value must be between -999,999,999 and 999,999,999" pop-up error.