Use the California Tax Form Calculator California Tax Form 5806: Underpayment of Estimated Tax by Corporations as a stand alone tax form calculator to quickly calculate specific amounts for your 2023 California state tax return. California Tax Form 5806: Underpayment of Estimated Tax by Corporations is also integrated into our comprehensive California State Tax Calculator where you can complete and save your calculations for later use. Alternatively you can use one of our Combined Federal and California State Tax Estimator to quickly calculate your salary, tax and take home pay in California.

Part I Figure the Underpayment | ||||||||||

1 | 1 | |||||||||

(a) | (b) | (c) | (d) | |||||||

2 | Installment due dates. See instructions | 2 | ||||||||

3 | Percentage required. See instructions | 3 | 30% | 70% less 1st | 70% less prior | 100% less prior | ||||

4 | Amount due. See instructions | 4 | ||||||||

5a | Amount paid or credited for each installment | 5a | ||||||||

b | Overpayment from previous installment. See instructions | 5b | ||||||||

6 | Add line 5a and line 5b | 6 | ||||||||

7 | Underpayment (subtract line 6 from line 4). See instructions. Overpayment (subtract line 4 from line 6). If line 7 shows an underpayment for any installment, go to Part IV, Exceptions Worksheets | 7 | ||||||||

Part II Exceptions to the Penalty. If Exception A, line 8a is met for all four installments, do not attach this form to the return. If Exception B or C is met, for any installment, attach form FTB 5806 to the back of Form 100, Form 100W, Form 100S or Form 109. | ||||||||||

(check the applicable boxes) | Yes | No | Yes | No | Yes | No | Yes | No | ||

8a | Exception A – Regular Corporations, line 26 | 8a | ||||||||

b | Exception A – Large Corporations, line 30. See instructions | 8b | ||||||||

9 | Exception B (line 42) met? | 9 | ||||||||

10 | Exception C (line 64) met? | 10 | ||||||||

Part III Figure the Penalty. If line 7 shows an underpayment for any installment and one of the three exceptions was not met, figure the penalty for that installment by completing line 11 through line 22. | ||||||||||

11 | Enter the earlier of the payment date, or the 15th day of the 3rd month after the close of the taxable year. Form 109 filers, see instructions | 11 | ||||||||

12 | Number of days from date shown on line 2 to date shown on line 11 | 12 | ||||||||

13 | Number of days on line 12 before 7/01/17, or the payment date, whichever is earlier | 13 | ||||||||

14 | Number of days on line 12 after 6/30/17 and before 1/01/18, or the payment date, whichever is earlier | 14 | ||||||||

15 | Number of days on line 12 after 12/31/17 and before 7/01/18, or the payment date, whichever is earlier. Calendar year corporations, see instructions | 15 | ||||||||

16 | For fiscal year corporations only. Number of days on line 12 after 6/30/18 and before 1/01/19. See instructions | 16 | ||||||||

17 | For fiscal year corporations only. Number of days on line 12 after 12/31/18 and before 2/15/19. See instructions | 17 | ||||||||

18 | Number of days on line 13/Number of days in taxable year * 4% * line 7 | 18 | ||||||||

19 | Number of days on line 14/Number of days in taxable year * 4% * line 7 | 19 | ||||||||

20 | Number of days on line 15/Number of days in taxable year * 4% * line 7 | 20 | ||||||||

21 | Number of days on line 16/Number of days in taxable year * (see instructions)% * line 7 | 21 | ||||||||

22 | Number of days on line 17/Number of days in taxable year * (see instructions)% * line 7 | 22 | ||||||||

22a | Add amounts for each column from line 18 through line 22 | 22a | ||||||||

22b | 22b | |||||||||

Part IV Exceptions Worksheets. Even if line 7 shows an underpayment for any installment, the Franchise Tax Board will not assess a penalty if timely payments were made and they equal or exceed the amount determined under any of the three exceptions for the same installment period. | ||||||||||

23 | 23 | |||||||||

(a) | (b) | (c) | (d) | |||||||

30% | 70% | 70% | 100% | |||||||

24 | Enter line 23 x the percentage shown | 24 | (not less than min.) | |||||||

25 | Amount paid by the installment due date (cumulative) | 25 | ||||||||

26 | If line 25 is greater than line 24, the exception was met. Check “Yes” here and check the applicable “Yes” box in Part ll, line 8a. If line 24 is greater than line 25, the exception was not met. Check “No” here and check the applicable “No” box in Part ll, line 8a | 26 | ||||||||

Exception A — Prior Year’s Tax — Large Corporations | ||||||||||

Use this exception only if prior year tax is less than current year tax. | ||||||||||

27 | 27 | |||||||||

1st Installment | 2nd Installment | |||||||||

28a | 28a | |||||||||

b | 28b | |||||||||

29 | 29 | |||||||||

30 | If line 29 is greater than line 28 for both installments, the exception is met. Check “Yes” here for each installment and check the applicable “Yes” box in Part II, line 8b. The exception to the penalty applies only if line 29 is greater than line 28 for both installments. If line 28 is greater than line 29 for either installment, the exception is not met. Check “No” here and check the applicable “No” box in Part II, line 8b | 30 | ||||||||

See instructions regarding amounts to use for installment 3 and installment 4. | ||||||||||

Exception B — Tax on Annualized Current Year Income | (a) | (b) | (c) | (d) | ||||||

Enter number of months for each period. See instructions ▸ | ||||||||||

31 | Enter taxable income for each annualization period | 31 | ||||||||

32 | Annualization amounts. See instructions | 32 | ||||||||

33a | Annualized taxable income. Multiply line 31 by line 32 | 33a | ||||||||

b | R&TC Section 23802(e) deduction (S corporations only) | 33b | ||||||||

c | Net income. Subtract line 33b from line 33a | 33c | ||||||||

34 | Tax. Multiply line 33c by the current tax rate | 34 | ||||||||

35 | Tax credits for each payment period | 35 | ||||||||

36 | Subtract line 35 from line 34 | 36 | ||||||||

37 | Other taxes* | 37 | ||||||||

38 | Total tax. Add line 36 and line 37 | 38 | ||||||||

39 | Applicable percentage. For short period returns (taxable year of less than 12 months), see the instructions for Part I, line 3 | 39 | 30% | 70% | 70% | 100% | ||||

40 | Installment due. Multiply line 38 by line 39 | 40 | ||||||||

41 | Amount paid by the installment due date (cumulative) | 41 | ||||||||

42 | If line 41 is greater than line 40, the exception was met. Check “Yes” here and check the applicable “Yes” box in Part ll, line 9. If line 40 is greater than line 41, the exception was not met. Check “No” here and check the applicable “No” box in Part ll, line 9. | 42 | ||||||||

*Include alternative minimum tax, S corporation taxes from Schedule D (100S) and from the excess net passive income, the QSub annual tax, installment amount credit recapture, and the minimum franchise tax. | ||||||||||

43 | Enter taxable income for the following periods: | 1st 3 months | 1st 5 months | 1st 8 months | 1st 11 months | |||||

a | Taxable year beginning in 2014 | 43a | ||||||||

b | Taxable year beginning in 2015 | 43b | ||||||||

c | Taxable year beginning in 2016 | 43c | ||||||||

44 | Enter taxable income for each period for the taxable year beginning in 2017 | 44 | ||||||||

45 | Enter taxable income for the following periods: | 1st 4 months | 1st 6 months | 1st 9 months | Entire year | |||||

a | Taxable year beginning in 2014 | 45a | ||||||||

b | Taxable year beginning in 2015 | 45b | ||||||||

c | Taxable year beginning in 2016 | 45c | ||||||||

46 | Divide the amount in each column on line 43a by the amount in column (d) on line 45a | 46 | ||||||||

47 | Divide the amount in each column on line 43b by the amount in column (d) on line 45b | 47 | ||||||||

48 | Divide the amount in each column on line 43c by the amount in column (d) on line 45c | 48 | ||||||||

49 | Add line 46 through line 48 | 49 | ||||||||

50 | Divide line 49 by 3 | 50 | ||||||||

51 | 1st 4 months | 1st 6 months | 1st 9 months | Entire year | ||||||

a | Divide line 44 by line 50 | 51a | ||||||||

b | R&TC Section 23802(e) deduction. (S corporations only) | 51b | ||||||||

c | Net income. Subtract line 51b from line 51a | 51c | ||||||||

52 | Tax. Multiply line 51c by the current tax rate | 52 | ||||||||

53 | Divide the amounts in column (a) through column (c) on line 45a by the amount in column (d) on line 45a | 53 | ||||||||

54 | Divide the amounts in column (a) through column (c) on line 45b by the amount in column (d) on line 45b | 54 | ||||||||

55 | Divide the amounts in column (a) through column (c) on line 45c by the amount in column (d) on line 45c | 55 | ||||||||

56 | Add line 53 through line 55 | 56 | ||||||||

57 | Divide line 56 by 3 | 57 | ||||||||

58 | Multiply the amounts in column (a) through column (c) of line 52 by the amounts in the corresponding column of line 57. In column (d), enter the amount from line 52, column (d) | 58 | ||||||||

59 | Tax credits for each payment period | 59 | ||||||||

60 | Subtract line 59 from line 58 | 60 | ||||||||

61 | Other taxes* | 61 | ||||||||

62 | Total tax. Add line 60 and line 61 | 62 | ||||||||

63 | Amount paid by the installment due date (cumulative) | 63 | ||||||||

64 | If line 63 is greater than line 62, the exception was met. Check “Yes” here and check the applicable “Yes” box in Part ll, line 10. If line 62 is greater than line 63, the exception was not met. Check “No” here and check the applicable “No” box in Part ll, line 10 | 64 |

**Tip:** use the California Tax Calculator to edit your refundable and non-refundable tax credits including California Tax Form 5806: Underpayment of Estimated Tax by Corporations. Complete, Calculate, print and or save your tax calculation for later use.

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