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openaccountants/skills/ny-estimated-tax.md

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v20New York
Not yet verified by an accountantContact accountant
1---
2name: ny-estimated-tax
3description: >
4 Use this skill whenever asked about New York State estimated tax (Form IT-2105) for self-employed individuals. Trigger on phrases like "IT-2105", "NY estimated tax", "New York quarterly tax", "MCTMT", "NYC estimated tax", "Yonkers tax", "NY underpayment penalty", "IT-2105.9", or any question about quarterly estimated income tax payments for New York State, NYC, or Yonkers. Covers quarterly instalment requirements, safe harbour rules, MCTMT estimated payments, underpayment penalty via IT-2105.9, and NYC estimated tax. ALWAYS read this skill before touching any NY estimated tax work.
5version: 2.0
6jurisdiction: US-NY
7tax_year: 2025
8category: state
9depends_on:
10 - us-tax-workflow-base
11validated: April 2026
12---
13 
14# NY Estimated Tax (IT-2105) -- Self-Employed Skill v2.0
15 
16## Section 1 -- Quick reference
17 
18| Field | Value |
19|---|---|
20| State | New York |
21| Tax | Quarterly estimated income tax (state + NYC + Yonkers + MCTMT) |
22| Forms | IT-2105 (voucher), IT-2105.9 (underpayment penalty) |
23| Primary legislation | NY Tax Law Section 685 |
24| Supporting legislation | NYC Admin Code 11-1701; NY Tax Law Art. 30-A (Yonkers) |
25| Authority | New York State Department of Taxation and Finance (NYSDTF) |
26| Portal | www.tax.ny.gov |
27| Currency | USD only |
28| Threshold | Estimated tax (state + city + MCTMT) after withholding >= $300 |
29| Safe harbours | 90% current year OR 100%/110% prior year |
30| Payment schedule | April 15, June 15, September 15, January 15 |
31| Contributor | Open Accountants Community |
32| Validated by | April 2026 |
33| Validation date | April 2026 |
34 
35**Payment schedule (TY2025):**
36 
37| Instalment | Due date |
38|---|---|
39| 1st | April 15, 2025 |
40| 2nd | June 15, 2025 |
41| 3rd | September 15, 2025 |
42| 4th | January 15, 2026 |
43 
44**Key rates:**
45 
46| Item | Value |
47|---|---|
48| MCTMT Zone 1 (self-employed) | 0.60% of NESE > $50,000 |
49| MCTMT Zone 2 (self-employed) | 0.34% of NESE > $50,000 |
50| NYC top resident rate | 3.876% |
51| Yonkers resident surcharge | 16.75% of NY state tax |
52| 110% prior-year threshold | NYAGI > $150,000 |
53 
54**Conservative defaults:**
55 
56| Ambiguity | Default |
57|---|---|
58| Prior year NYAGI unknown | Assume > $150K, use 110% safe harbour |
59| MCTMT zone uncertain | Confirm county of self-employment |
60| NYC residency unclear | Do not include NYC tax unless confirmed NYC resident |
61| UBT credit available | Include only if taxpayer files NYC UBT return |
62| Annualized method | Default to equal instalments; flag annualized option for reviewer |
63 
64---
65 
66## Section 2 -- Required inputs and refusal catalogue
67 
68### Required inputs
69 
70**Minimum viable** -- expected NY state tax, NYC tax (if applicable), MCTMT (if applicable), prior year NY tax return, expected withholding.
71 
72**Recommended** -- prior year NYAGI (for 110% test), county of self-employment (for MCTMT zone), NYC UBT credit estimate.
73 
74**Ideal** -- complete prior year IT-201, current year income projection, W-2 withholding estimates, NYC UBT return data.
75 
76**Refusal policy if minimum is missing -- SOFT WARN.** Without prior year data, the safe harbour cannot be computed.
77 
78### Refusal catalogue
79 
80**R-NY-ET-1 -- Corporate estimated tax (CT-400).** Trigger: corporation. Message: "Corporate estimated tax has different rules."
81 
82**R-NY-ET-2 -- Partnership/fiduciary estimated tax.** Trigger: partnership or trust. Message: "Partnership and fiduciary estimated tax are outside this skill."
83 
84**R-NY-ET-3 -- PTET estimated payments.** Trigger: pass-through entity tax. Message: "PTET estimated payments are outside this skill."
85 
86**R-NY-ET-4 -- Non-resident filers.** Trigger: non-resident of NY. Message: "Non-resident estimated tax has different rules."
87 
88---
89 
90## Section 3 -- Payment pattern library
91 
92This is the deterministic pre-classifier for bank statement transactions. When a debit matches a pattern below, classify it as a NY estimated tax payment.
93 
94### 3.1 NYSDTF estimated tax debits
95 
96| Pattern | Treatment | Notes |
97|---|---|---|
98| NYS TAX, NY STATE TAX, NYSDTF | NY estimated payment | Match with Apr/Jun/Sep/Jan timing |
99| IT-2105, IT2105 | NY estimated payment | Form number reference |
100| NEW YORK ESTIMATED TAX | NY estimated payment | Explicit description |
101| TAX.NY.GOV PAYMENT | NY estimated payment | Online payment |
102 
103### 3.2 Timing-based identification
104 
105| Debit date range | Likely instalment | Confidence |
106|---|---|---|
107| 10 April -- 20 April | 1st instalment | High if NY tax payee |
108| 10 June -- 20 June | 2nd instalment | High |
109| 10 September -- 20 September | 3rd instalment | High |
110| 10 January -- 20 January | 4th instalment | High |
111 
112### 3.3 Related but NOT NY estimated tax
113 
114| Pattern | Treatment | Notes |
115|---|---|---|
116| IRS, FEDERAL ESTIMATED | EXCLUDE | Federal estimated tax |
117| NYC DOF, NYC PROPERTY | EXCLUDE | NYC property tax |
118| NY SALES TAX | EXCLUDE | Sales tax payment |
119| NYS PENALTY, NYS INTEREST | EXCLUDE | Penalty/interest |
120| IT-201 BALANCE | Flag for reviewer | Annual return balance, not estimated |
121 
122---
123 
124## Section 4 -- Worked examples
125 
126### Example 1 -- Standard NYC freelancer
127 
128**Input:** Single NYC resident. NYAGI $120,000. NY tax $6,500. NYC tax $3,800. MCTMT ($120,000 - $50,000) x 0.60% = $420. No withholding.
129 
130| Component | Amount |
131|---|---|
132| NY state tax | $6,500 |
133| NYC tax | $3,800 |
134| MCTMT | $420 |
135| **Total** | **$10,720** |
136 
137Required: 90% x $10,720 = $9,648 (or 100% prior if lower). Quarterly: $2,412.
138 
139### Example 2 -- High-income, 110% prior year
140 
141**Input:** Single. NYAGI $200,000. Current year total $18,000. Prior year $14,000.
142 
143**Computation:** 90% current = $16,200. 110% prior = $15,400. Required = $15,400 (lesser). Quarterly = $3,850.
144 
145### Example 3 -- Below threshold
146 
147**Input:** NYC resident. Estimated tax after withholding = $250.
148 
149**Output:** $250 < $300 threshold. No estimated payments required.
150 
151### Example 4 -- Yonkers resident
152 
153**Input:** Yonkers resident. NY state tax $5,000. Yonkers surcharge = $5,000 x 16.75% = $837.50.
154 
155**Output:** Include $837.50 in estimated tax total.
156 
157### Example 5 -- MCTMT Zone 2 only
158 
159**Input:** Westchester resident (Zone 2). NESE $80,000.
160 
161**Output:** MCTMT = ($80,000 - $50,000) x 0.34% = $102.
162 
163---
164 
165## Section 5 -- Computation rules
166 
167### 5.1 Determine total estimated tax
168 
169```
170total_estimated = NY_state_tax + NYC_tax + Yonkers_tax + MCTMT
171net_estimated = total_estimated - expected_withholding - credits
172if net_estimated < 300: no estimated payments required
173```
174 
175### 5.2 Required annual payment
176 
177Required = lesser of:
178- 90% of current year tax, OR
179- 100% of prior year tax (110% if NYAGI > $150,000)
180 
181### 5.3 Quarterly instalments
182 
183Each instalment = required annual payment / 4 (25% each).
184 
185### 5.4 NY state tax computation
186 
187Federal AGI + NY additions - NY subtractions = NYAGI. Apply NY rate schedule (4% to 10.9%). Subtract NY credits.
188 
189### 5.5 NYC resident tax
190 
191NYC taxable income x NYC rates (3.078% to 3.876%). Subtract NYC household credit and UBT credit.
192 
193### 5.6 MCTMT
194 
195Self-employed in MCTD (12 counties): NESE above $50,000 x zone rate (0.60% Zone 1, 0.34% Zone 2).
196 
197### 5.7 Yonkers
198 
199Resident: 16.75% of NY state tax. Nonresident working in Yonkers: 0.5% of Yonkers-source earnings.
200 
201---
202 
203## Section 6 -- Penalties and interest
204 
205### 6.1 Underpayment penalty
206 
207Computed on IT-2105.9. Rate varies quarterly (set by NYSDTF). Applied per-quarter on the shortfall from each instalment due date.
208 
209### 6.2 Safe harbour protection
210 
211If payments meet the required annual payment (lesser of 90% current or 100%/110% prior), no penalty.
212 
213### 6.3 Annualized income instalment method
214 
215IT-2105.9 allows annualized method for uneven income. Computes income actually earned through each quarter-end. Reduces early-quarter payments for seasonal freelancers.
216 
217---
218 
219## Section 7 -- Filing and payment procedure
220 
221**Paper vouchers:** Form IT-2105 mailed to NYSDTF.
222 
223**Online:** Pay at www.tax.ny.gov (no voucher needed).
224 
225**Prior year overpayment:** Applied to reduce 1st quarter payment. Document on voucher.
226 
227---
228 
229## Section 8 -- Edge cases
230 
231**EC1 -- 110% prior-year rule.** NYAGI > $150,000 requires 110% of prior year (not 100%). Mirrors federal rule.
232 
233**EC2 -- MCTMT included in estimated tax.** MCTMT is on Form IT-201 (Lines 54a/54b). NOT a separate filing.
234 
235**EC3 -- NYC UBT credit.** IT-219 credit reduces NYC estimated tax. Include when estimating.
236 
237**EC4 -- First year of self-employment.** Prior year safe harbour = $0. Use 90% current year.
238 
239**EC5 -- Annualized income method.** Seasonal freelancer: use IT-2105.9 to reduce early-quarter payments.
240 
241**EC6 -- Overpayment from prior year.** Applied to 1st quarter estimated payment.
242 
243---
244 
245## Section 9 -- Self-checks
246 
247Before delivering output, verify:
248 
249- [ ] $300 threshold applied correctly
250- [ ] All tax layers included (state + city + Yonkers + MCTMT as applicable)
251- [ ] 110% prior-year rule applied for NYAGI > $150,000
252- [ ] MCTMT computed with correct zone rate and $50,000 threshold
253- [ ] NYC UBT credit offset included if applicable
254- [ ] Quarterly payments divided evenly (25% each)
255- [ ] Withholding and prior-year overpayment credits subtracted
256- [ ] Reviewer brief notes which safe harbour method was used
257- [ ] Due dates confirmed (Apr 15, Jun 15, Sep 15, Jan 15)
258- [ ] Output labelled as estimated until reviewer confirms
259 
260---
261 
262## Section 10 -- Test suite
263 
264### Test 1 -- NYC freelancer
265**Input:** NYAGI $120,000. NY tax $6,500. NYC $3,800. MCTMT $420. No withholding.
266**Expected:** Total $10,720. Required 90% = $9,648. Quarterly $2,412.
267 
268### Test 2 -- High-income 110% rule
269**Input:** NYAGI $200,000. Current $18,000. Prior $14,000.
270**Expected:** 90% current = $16,200. 110% prior = $15,400. Required = $15,400. Quarterly = $3,850.
271 
272### Test 3 -- Below threshold
273**Input:** Estimated tax after withholding = $250.
274**Expected:** No payments required.
275 
276### Test 4 -- Yonkers resident
277**Input:** NY state tax $5,000.
278**Expected:** Yonkers = $837.50. Include in total.
279 
280### Test 5 -- MCTMT Zone 2
281**Input:** Westchester. NESE $80,000.
282**Expected:** MCTMT = $102.
283 
284### Test 6 -- First year
285**Input:** No prior NY return.
286**Expected:** Prior year safe harbour = $0. Use 90% current.
287 
288---
289 
290## Prohibitions
291 
292- NEVER omit MCTMT from estimated tax calculations
293- NEVER use 100% prior-year safe harbour for NYAGI > $150,000 -- use 110%
294- NEVER estimate NYC tax for non-NYC residents
295- NEVER ignore the NYC UBT credit when estimating NYC tax
296- NEVER advise on penalty waiver requests -- procedural matter
297- NEVER confuse NY estimated tax with federal estimated tax
298 
299---
300 
301## Disclaimer
302 
303This skill and its outputs are provided for informational and computational purposes only and do not constitute tax, legal, or financial advice. Open Accountants and its contributors accept no liability for any errors, omissions, or outcomes arising from the use of this skill. All outputs must be reviewed and signed off by a qualified professional (such as a CPA, EA, tax attorney, or equivalent licensed practitioner in your jurisdiction) before filing or acting upon.
304 
305The most up-to-date, verified version of this skill is maintained at [openaccountants.com](https://openaccountants.com). Log in to access the latest version, request a professional review from a licensed accountant, and track updates as tax law changes.
306 

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Use this skill whenever asked about New York State estimated tax (Form IT-2105) for self-employed individuals. Trigger on phrases like "IT-2105", "NY estimated tax", "New York quarterly tax", "MCTMT", "NYC estimated tax", "Yonkers tax", "NY underpayment penalty", "IT-2105.9", or any question about quarterly estimated income tax payments for New York State, NYC, or Yonkers. Covers quarterly instalment requirements, safe harbour rules, MCTMT estimated payments, underpayment penalty via IT-2105.9, and NYC estimated tax. ALWAYS read this skill before touching any NY estimated tax work.

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