B

Post-Retirement Tax Calendar

3.85

Derivation Chain

Step 1 Retirement Pension optimization
→
Step 2 Post-retirement income structure changes
→
Step 3 Missed tax filing deadlines and refunds in the first year after retirement

Problem

The tax structure in the first year after retirement is completely different from during employment. Retirement income tax settlement, mid-year year-end tax adjustment, comprehensive income tax filing (May), health insurance dependent status determination (November), and property tax/comprehensive real estate tax payments all overlap — and the company HR team no longer handles them. In particular, the method of receiving retirement pay (lump sum vs. Retirement Pension) changes the following May's comprehensive income tax filing requirements, and failure to account for this results in penalty taxes. Cases of missing 500,000-2,000,000 KRW (~$375-$1,500) in refunds or paying penalty taxes in the first year of retirement are common.

Solution

On a web interface, users enter their retirement date, retirement pay receipt method, and other income sources (Rental, interest, dividends). The service then: (1) auto-generates a month-by-month tax and insurance event calendar for the 12 months post-retirement, (2) provides filing/payment deadlines and document preparation checklists for each event, (3) calculates estimated mid-year year-end tax adjustment refund, (4) sends D-30 and D-7 deadline reminders.

Target: Ages 53-60, retiring within 3 months or in their first year post-retirement, former employees who have lost company HR team support
Revenue Model: Basic calendar generation Free, custom filing guide (document preparation + HomeTax screenshot tutorial) $4.40 (5,900 KRW) Per Transaction, Annual Subscription (event alerts + updates) $21.70 (29,000 KRW)
Ecosystem Role: Regulation
MVP Estimate: 2_weeks

NUMR-V Scores

N Novelty
3.0/5
U Urgency
4.0/5
M Market
3.0/5
R Realizability
5.0/5
V Validation
3.0/5
NUMR-V Scoring System
N Novelty1-5How uncommon the service is in market context.
U Urgency1-5How urgently users need this problem solved now.
M Market1-5Market size and growth potential from proxy indicators.
R Realizability1-5Buildability for a small team with realistic constraints.
V Validation1-5Validation signal quality from competition and demand data.
Each dimension is scored 1-5 and weighted into grade S/A/B/C/D.
SaaS N=.15 U=.20 M=.15 R=.30 V=.20 Senior N=.25 U=.25 M=.05 R=.30 V=.15

Feasibility (73%)

Tech Complexity
29.3/40
Data Availability
23.3/25
MVP Timeline
20.0/20
API Bonus
0.0/15
Feasibility Breakdown
Tech Complexity/ 40Difficulty of core implementation stack.
Data Availability/ 25Practical availability and cost of required data.
MVP Timeline/ 20Expected time to ship a usable MVP.
API Bonus/ 15Bonus for viable public API leverage.
Total 100 points; below 50% is filtered out.

Market Validation (56/100)

Competition
8.0/20
Market Demand
6.2/20
Timing
14.0/20
Revenue Signals
10.5/15
Pick-Axe Fit
10.5/15
Solo Buildability
7.0/10
Validation Breakdown
Competition/ 20Signal quality from competitor landscape.
Market Demand/ 20Demand proxies from search and mention patterns.
Timing/ 20Fit with current shifts in tech, behavior, and regulation.
Revenue Signals/ 15Reference evidence for monetization viability.
Pick-Axe Fit/ 15How well the concept serves participants in a trend.
Solo Buildability/ 10Practicality for lean-team implementation.
Total 100 points; below 50 is filtered out.

Technical Requirements

Frontend [medium] Backend [medium] Infrastructure [low]
Dashboard