Turbo Tax Home & Business 2023 - Schedule C - Line 27a - Can't change this number

I assume you are talking about making changes to Schedule C in forms mode. Above line 48 there is a box where you enter "other expenses." Enter a description and amount for each expense. The amount on line 48 and line 27a is the total of the expenses that are entered in that box.

Additionally, if you entered those expenses in the interview section of the program. you can edit those expenses in Forms mode using the Schedule C Worksheet on the Miscellaneous Expense section of the worksheet.