Not tax advice. Computation tools only. Have a professional check your work before filing.
openaccountants
openaccountants/skills/ie-preliminary-tax.md

Use this skill with your AI agent

View on GitHub

Paste this skill into your AI agent's context, or save the file to your project. Works with any AI agent that reads markdown.

ie-preliminary-tax.md314 lines12.8 KB
v20Ireland
Not yet verified by an accountantContact accountant
1---
2name: ie-preliminary-tax
3description: >
4 Use this skill whenever asked about Irish Preliminary Tax for self-employed individuals. Trigger on phrases like "preliminary tax Ireland", "Form 11", "self-assessed tax Ireland", "October 31 deadline", "ROS filing", "100% rule preliminary tax", "90% rule Ireland", or any question about estimated tax payment obligations for a self-employed client in Ireland. Covers the 100%/90% prior-year/current-year rules, payment deadlines, and surcharges. ALWAYS read this skill before touching any Ireland preliminary tax work.
5version: 2.0
6jurisdiction: IE
7tax_year: 2025
8category: international
9depends_on:
10 - income-tax-workflow-base
11---
12 
13# Ireland Preliminary Tax -- Self-Employed Skill v2.0
14 
15## Section 1 -- Quick reference
16 
17| Field | Value |
18|---|---|
19| Country | Ireland |
20| Tax | Preliminary income tax (income tax + USC + PRSI Class S) |
21| Primary legislation | TCA 1997, Part 41A (Self-Assessment), ss. 952-959 |
22| Supporting legislation | TCA 1997, s.1080 (interest), s.1084 (surcharges); Finance Acts |
23| Authority | Revenue Commissioners (Revenue) |
24| Portal | ROS (Revenue Online Service) |
25| Currency | EUR only |
26| Payment schedule | Annual lump sum: 31 October (paper) or ~14 November (ROS) |
27| Safe harbours | 100% of prior year liability OR 90% of current year liability |
28| De minimis | Prior year liability <= EUR 200: no preliminary tax required |
29| Components | Income tax + USC + PRSI (Class S at 4%) |
30| CGT | Separate payment dates (15 Dec / 31 Jan) -- NOT part of preliminary tax |
31| Contributor | Open Accountants Community |
32| Validated by | Pending -- requires validation by Irish Chartered Accountant or CTA |
33| Validation date | Pending |
34 
35**Key dates (tax year 2025):**
36 
37| Event | Paper deadline | ROS deadline |
38|---|---|---|
39| Pay 2025 preliminary tax | 31 Oct 2025 | ~14 Nov 2025 |
40| File 2024 Form 11 | 31 Oct 2025 | ~14 Nov 2025 |
41| Pay 2024 balance of tax | 31 Oct 2025 | ~14 Nov 2025 |
42 
43**Conservative defaults:**
44 
45| Ambiguity | Default |
46|---|---|
47| Rule selection unclear | Use 100% of prior year (safe, no estimation needed) |
48| Filing method unclear | Confirm paper vs ROS (2-week difference in deadline) |
49| CGT included in preliminary | EXCLUDE -- separate dates |
50| First year of self-assessment | Must use 90% rule (no prior year available) |
51| Prior year liability unknown | STOP -- the 100% rule requires prior year figure |
52 
53---
54 
55## Section 2 -- Required inputs and refusal catalogue
56 
57### Required inputs
58 
59**Minimum viable** -- prior year final tax liability (income tax + USC + PRSI) for the 100% rule, OR current year estimated income for the 90% rule.
60 
61**Recommended** -- filing method (paper vs ROS), PAYE credits from employment, CGT obligations (separate), current year income expectations.
62 
63**Ideal** -- complete prior year Form 11, Revenue assessment, current year P&L projection, PAYE certificates.
64 
65**Refusal policy if minimum is missing -- HARD STOP for 100% rule.** Without prior year liability, the 100% rule cannot be computed. For 90% rule, current year estimates needed.
66 
67### Refusal catalogue
68 
69**R-IE-PT-1 -- Trust/corporate preliminary tax.** Trigger: client asks about corporate or trust preliminary tax. Message: "This skill covers self-employed individuals only."
70 
71**R-IE-PT-2 -- CGT computation.** Trigger: client asks about CGT preliminary tax computation. Message: "CGT has separate payment dates (15 December / 31 January) and is NOT part of the 31 October preliminary tax payment. CGT computation is outside this skill."
72 
73**R-IE-PT-3 -- Non-resident self-assessment.** Trigger: non-resident client. Message: "Non-resident self-assessment is outside this skill."
74 
75---
76 
77## Section 3 -- Payment pattern library
78 
79This is the deterministic pre-classifier for bank statement transactions. When a debit matches a pattern below, classify it as a preliminary tax payment.
80 
81### 3.1 Revenue preliminary tax debits
82 
83| Pattern | Treatment | Notes |
84|---|---|---|
85| REVENUE, REVENUE COMMISSIONERS | Preliminary tax payment | Match with October/November timing |
86| ROS PAYMENT, ROS DEBIT | Preliminary tax payment | ROS online payment |
87| PRELIMINARY TAX, PRELIM TAX | Preliminary tax payment | Explicit description |
88| FORM 11, SELF ASSESSMENT | Preliminary tax or balance payment | Distinguish by timing |
89| INCOME TAX REVENUE | Preliminary tax payment | Generic description |
90 
91### 3.2 Timing-based identification
92 
93| Debit date range | Likely payment | Confidence |
94|---|---|---|
95| 15 October -- 5 November | Preliminary tax (paper deadline 31 Oct) | High if Revenue payee |
96| 1 November -- 20 November | Preliminary tax (ROS deadline ~14 Nov) | High |
97| Same date: large single debit | Combined: balance of prior year + current year preliminary | Flag for reviewer to split |
98 
99### 3.3 Related but NOT preliminary tax
100 
101| Pattern | Treatment | Notes |
102|---|---|---|
103| CGT, CAPITAL GAINS TAX | EXCLUDE | Separate obligation, separate dates |
104| PAYE, EMPLOYER PAYE | EXCLUDE | Employer PAYE payment |
105| VAT, VAT3 RETURN | EXCLUDE | VAT payment |
106| PRSI EMPLOYER | EXCLUDE | Employer PRSI |
107| LOCAL PROPERTY TAX, LPT | EXCLUDE | Property tax |
108| USC DIRECT | EXCLUDE | USC coded through employment |
109| SURCHARGE, INTEREST REVENUE | EXCLUDE | Penalty/interest |
110 
111### 3.4 Direct debit identification
112 
113If the client pays preliminary tax by direct debit instalments (105% of pre-prior-year rule), monthly debits to Revenue throughout the year are direct debit preliminary tax payments. Flag for reviewer.
114 
115---
116 
117## Section 4 -- Worked examples
118 
119### Example 1 -- Standard 100% rule
120 
121**Input:** Prior year final liability = EUR 15,000 (income tax EUR 9,000 + USC EUR 3,500 + PRSI EUR 2,500).
122 
123**Output:** Preliminary tax = EUR 15,000. Due 31 Oct (paper) or ~14 Nov (ROS).
124 
125### Example 2 -- 90% rule, income drop
126 
127**Input:** Prior year liability = EUR 30,000. Current year estimated liability = EUR 10,000.
128 
129**Output:** 90% rule: EUR 10,000 x 90% = EUR 9,000. Saves EUR 21,000 vs 100% rule. Risk: if actual > estimate, interest applies on shortfall.
130 
131### Example 3 -- First year of self-employment
132 
133**Input:** First year, no prior year self-assessed liability. Estimated income EUR 60,000. Estimated tax: IT EUR 11,000 + USC EUR 2,400 + PRSI EUR 2,400 = EUR 15,800.
134 
135**Output:** 90% rule (only option). Preliminary = EUR 15,800 x 90% = EUR 14,220.
136 
137### Example 4 -- De minimis
138 
139**Input:** Prior year liability = EUR 120.
140 
141**Output:** Below EUR 200 de minimis. No preliminary tax required. Still must file Form 11.
142 
143### Example 5 -- CGT separate payment
144 
145**Input:** Income preliminary EUR 12,000 (due 31 Oct). CGT on June disposal = EUR 8,250.
146 
147**Output:** Income preliminary: EUR 12,000 due 31 Oct. CGT: EUR 8,250 due 15 Dec. Two separate payments.
148 
149### Example 6 -- Bank statement classification
150 
151**Input line:** `31.10.2025 ; REVENUE COMMISSIONERS ROS ; DEBIT ; PRELIMINARY TAX 2025 ; -15,000.00 ; EUR`
152 
153**Classification:** Preliminary tax for 2025. Tax payment -- not a deductible expense.
154 
155---
156 
157## Section 5 -- Computation rules
158 
159### 5.1 Two safe harbour rules
160 
161| Rule | Amount | When |
162|---|---|---|
163| 100% of prior year | 100% of prior year final liability | Safe default -- no estimation needed |
164| 90% of current year | 90% of current year estimated liability | If current year significantly lower |
165 
166Taxpayer meets obligation if they pay at least ONE of these amounts.
167 
168### 5.2 What constitutes "tax liability"
169 
170Preliminary tax = income tax + USC + PRSI (Class S at 4%). PRSI minimum = EUR 500 if income > EUR 5,000.
171 
172### 5.3 Computation steps
173 
174```
175prior_year_liability = income_tax + USC + PRSI
176option_A = prior_year_liability x 100%
177option_B = estimated_current_year_liability x 90%
178preliminary_tax = min(option_A, option_B) (or simply pay option_A for safety)
179net_due = preliminary_tax - PAYE_credits - withholding_tax
180```
181 
182### 5.4 105% of pre-prior-year (direct debit)
183 
184For clients on direct debit: 105% of the pre-prior-year liability, spread in equal monthly instalments. This is a third safe harbour.
185 
186### 5.5 First year rule
187 
188First year of self-assessment: 100% rule is unavailable (no prior year). Must use 90% of estimated current year.
189 
190---
191 
192## Section 6 -- Penalties and interest
193 
194### 6.1 Interest on late/insufficient payment
195 
196| Element | Rate |
197|---|---|
198| Daily rate | 0.0219% per day |
199| Approximate annual rate | ~8% per annum |
200| Runs from | Due date to actual payment date |
201 
202### 6.2 Surcharge for late return filing
203 
204| Delay | Surcharge |
205|---|---|
206| Within 2 months of deadline | 5% of tax due (max EUR 12,695) |
207| More than 2 months late | 10% of tax due (max EUR 63,485) |
208 
209The surcharge applies to the RETURN, not the payment. Even if payment is on time, a late return triggers the surcharge.
210 
211---
212 
213## Section 7 -- PRSI Class S
214 
215| Parameter | Value |
216|---|---|
217| Rate | 4% |
218| Minimum annual contribution | EUR 500 (even if 4% < EUR 500) |
219| Applied to | All self-employment income, no upper limit |
220| Exemption | Income below EUR 5,000 |
221 
222PRSI is included in the preliminary tax payment and collected through self-assessment.
223 
224---
225 
226## Section 8 -- Edge cases
227 
228**EC1 -- Prior year liability under EUR 200.** De minimis: no preliminary tax. Must still file Form 11.
229 
230**EC2 -- Income dropped significantly.** Use 90% rule. Risk: interest if estimate too low.
231 
232**EC3 -- First year of self-employment.** No prior year liability. Must estimate and pay 90%.
233 
234**EC4 -- ROS vs paper deadline confusion.** Paper: strictly 31 October. ROS: ~14 November (exact date published annually). Extension ONLY for ROS filers who both file AND pay through ROS.
235 
236**EC5 -- Capital gain in August.** CGT = gain x 33%. Due 15 December. Separate from 31 Oct preliminary.
237 
238**EC6 -- PAYE employee with rental income.** Preliminary tax on rental income (Case V). 100% rule on prior year Case V liability. PAYE credits offset income tax.
239 
240**EC7 -- Direct debit (105% rule).** Monthly spread of 105% of pre-prior-year. Flag for reviewer.
241 
242**EC8 -- Surcharge on late return.** Payment on time but return 6 weeks late: 5% surcharge applies. Surcharge triggered by return, not payment.
243 
244---
245 
246## Section 9 -- Self-checks
247 
248Before delivering output, verify:
249 
250- [ ] Safe harbour rule selected (100% prior / 90% current / 105% pre-prior DD)
251- [ ] All three components included (income tax + USC + PRSI)
252- [ ] PRSI minimum EUR 500 checked if income > EUR 5,000
253- [ ] CGT excluded from 31 October payment
254- [ ] Correct deadline used (paper 31 Oct vs ROS ~14 Nov)
255- [ ] De minimis EUR 200 threshold checked
256- [ ] First-year rule applied if no prior year
257- [ ] Surcharge risk noted for late filing
258- [ ] Interest rate quoted (0.0219%/day)
259- [ ] Output labelled as estimated until Irish CA or CTA confirms
260 
261---
262 
263## Section 10 -- Test suite
264 
265### Test 1 -- Standard 100% rule
266**Input:** Prior year liability EUR 15,000.
267**Expected:** Preliminary = EUR 15,000. Due 31 Oct or ~14 Nov (ROS).
268 
269### Test 2 -- 90% rule
270**Input:** Prior year EUR 30,000. Estimated current = EUR 10,000.
271**Expected:** 90% x EUR 10,000 = EUR 9,000. Interest risk flagged.
272 
273### Test 3 -- First year
274**Input:** First year. Estimated liability EUR 15,800.
275**Expected:** 90% = EUR 14,220.
276 
277### Test 4 -- De minimis
278**Input:** Prior year liability EUR 120.
279**Expected:** No preliminary tax. Must still file Form 11.
280 
281### Test 5 -- CGT separate
282**Input:** Income preliminary EUR 12,000. CGT EUR 8,250.
283**Expected:** EUR 12,000 due 31 Oct. EUR 8,250 due 15 Dec.
284 
285### Test 6 -- Surcharge
286**Input:** Tax EUR 20,000. Return filed 6 weeks late.
287**Expected:** 5% surcharge = EUR 1,000.
288 
289### Test 7 -- PAYE + self-employment
290**Input:** PAYE salary EUR 50,000. SE income EUR 25,000. Prior year SE component EUR 8,000.
291**Expected:** Preliminary = EUR 8,000 (100% of prior year SE portion).
292 
293---
294 
295## Prohibitions
296 
297- NEVER tell a client the 100% rule requires estimating current year -- it does NOT
298- NEVER confuse paper deadline (31 Oct) with ROS deadline (~mid-Nov)
299- NEVER include CGT in the 31 October payment -- separate dates
300- NEVER forget USC and PRSI when computing "tax liability"
301- NEVER ignore the surcharge for late filing -- applies even if payment is on time
302- NEVER apply the 105% rule without confirming direct debit arrangement
303- NEVER tell a first-year self-employed person to use the 100% rule -- must use 90%
304- NEVER ignore the EUR 200 de minimis threshold
305- NEVER present preliminary tax as final -- balance settled with Form 11
306 
307---
308 
309## Disclaimer
310 
311This 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.
312 
313The 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.
314 

Run this skill, then get an accountant to check it

After running the full skill pack in your AI agent, sign up and upload your worksheet. We'll connect you with a trusted accountant in our network who can review your numbers before you file.

Sign up to submit a review

Quality

Q3: AI-drafted

AI-generated with structure and citations. Not independently verified.

Needs deep research against tax authority websites to reach Q2.

Accountant Review

Not yet reviewed
0/34

About

Use this skill whenever asked about Irish Preliminary Tax for self-employed individuals. Trigger on phrases like "preliminary tax Ireland", "Form 11", "self-assessed tax Ireland", "October 31 deadline", "ROS filing", "100% rule preliminary tax", "90% rule Ireland", or any question about estimated tax payment obligations for a self-employed client in Ireland. Covers the 100%/90% prior-year/current-year rules, payment deadlines, and surcharges. ALWAYS read this skill before touching any Ireland preliminary tax work.

IEty-2025

Use this skill

This skill is open source and free to use in any AI agent. Copy it, download it, or clone the repo. If you find an error, flag it — a licensed accountant will review.

3 of 6 in the IE workflow: