Business Requirements Document (BRD)
Business Requirements Document (BRD): Bilko
Project: Bilko — Balkan Accounting SaaS
Version: 1.0
Date: 2026-02-25
Author: John (AI Director)
Status: Final
Reviewers: Alem Bašić (CEO)
Document History
| Version |
Date |
Author |
Changes |
| 0.1 |
2026-02-23 |
John (AI Director) |
Initial draft — Phase 1 Serbia focus |
| 1.0 |
2026-02-25 |
John (AI Director) |
Finalized for v1.0 release |
1. Executive Summary
Project Overview:
Bilko is a cloud SaaS accounting platform for Balkan SMBs — the first modern, cloud-native tool purpose-built for Serbian, Bosnian, and Croatian small businesses with full local tax compliance, native language support, and affordable pricing. Phase 1 targets Serbia (300K+ active SMBs) where e-invoicing via SEF has been mandatory since 2023.
Business Problem:
348,000+ Balkan SMBs have no affordable, modern, cloud-native accounting tool with full local regulatory compliance — they are forced to choose between over-engineered ERP software (Pantheon, Minimax at €150+/month), global tools with no Balkan compliance (QuickBooks/Xero), or manual spreadsheets that violate SEF e-invoicing law.
Proposed Solution:
Bilko — a Fiken-inspired SaaS at €8-25/month with SEF e-invoicing, PDV auto-calculation, double-entry bookkeeping, bank reconciliation, and financial reports in Serbian/Bosnian/Croatian.
Expected Outcomes:
- 100 paying organizations within 90 days of Serbia launch
- €500 MRR by end of Month 3 post-launch
- 80% activation rate (users create their first invoice within 7 days)
- Full SEF compliance for all invoices submitted through Bilko
Investment: €11,000–17,000 EUR | Timeline: ~10 weeks to Serbia launch | Priority: High — CEO GO decision 2026-02-20
2. Business Objectives & Goals
| ID |
Objective |
Description |
Target |
Timeframe |
| BO-01 |
Launch compliant Serbia product |
Deliver a fully SEF-compliant invoicing and accounting platform for Serbian SMBs |
Production launch with 0 critical compliance bugs |
2026-05-01 |
| BO-02 |
Acquire first paying customers |
Onboard 100 paying organizations in Serbia within 90 days of launch |
100 orgs × avg €15/month |
By 2026-08-01 |
| BO-03 |
Achieve product-market fit signals |
Reach NPS > 50 and < 5% monthly churn among early adopters |
NPS ≥ 50, churn ≤ 5%/month |
60 days post-launch |
| BO-04 |
Establish Balkan market position |
Launch Croatia by Q4 2026, establish Bilko as the leading Balkan cloud accounting brand |
Croatia beta by 2026-10-01 |
2026-10-01 |
| BO-05 |
Generate ARR for ALAI |
Bilko becomes a revenue pillar for ALAI Holding, reducing consulting dependency |
€50K ARR by 2026-12-31 |
2026-12-31 |
Alignment to Strategic Goals:
- ALAI product portfolio: Bilko is ALAI's first B2B SaaS product — validates the product-building capability and creates recurring revenue
- Balkan market expansion: Bilko establishes ALAI's brand and infrastructure in Serbia, Croatia, and BiH for future products
3. Current State Analysis (AS-IS)
3.1 Current Process Overview
A typical Serbian SMB owner currently manages accounting through one of three workflows:
- Pantheon/Minimax desktop software — installed locally, managed by an accountant, significant monthly cost (€100-200+), complex interface
- Manual spreadsheet + paper invoices — technically illegal post-2023 SEF mandate; exposes business to fines
- Outsourced accountant only — accountant submits SEF invoices manually; owner has no real-time visibility into finances
None of these provide: (a) real-time cloud access, (b) affordable self-service, or (c) simple enough UX for non-accountants.
3.2 AS-IS Process Flow
flowchart LR
A([SMB Owner]) --> B[Create invoice in Excel/Word]
B --> C{SEF registered?}
C -->|Yes| D[Export to SEF format manually]
C -->|No| E[Send paper/PDF invoice — non-compliant]
D --> F[Submit to efaktura.gov.rs portal]
E --> G[Risk of fine: up to 500K RSD]
F --> H[Track payment manually in spreadsheet]
H --> I[Send data to accountant monthly]
I --> J[Accountant reconciles, prepares PDV report]
J --> K[Submit PDV to Poreska Uprava — 15th of month]
3.3 Current Systems & Tools
3.4 Current State Pain Points
| # |
Pain Point |
Category |
Affected Users |
Business Impact |
Severity |
| PP-01 |
SEF compliance is time-consuming without dedicated software |
Process |
All B2B SMBs in Serbia |
1-2 hours per invoice in manual workflow; fine risk |
High |
| PP-02 |
Existing solutions (Pantheon) cost as much as a part-time salary |
Technology |
Budget-constrained SMBs |
80% of SMBs cannot justify >€50/month |
High |
| PP-03 |
No local language + local compliance in affordable tools |
Technology |
Non-English speakers |
QuickBooks/Xero require English + have no SEF |
High |
| PP-04 |
Accountants cannot manage multiple clients from one platform |
Process |
Bookkeepers |
2-3 hours/client/month in manual reconciliation |
Medium |
| PP-05 |
No real-time financial visibility for business owners |
Data |
SMB owners |
Decisions made on stale monthly reports |
Medium |
| PP-06 |
Multi-currency transactions (BAM, EUR, RSD) managed manually |
Data |
Import/export businesses |
Exchange rate errors in VAT calculations |
Medium |
3.5 Current State Metrics (Baseline)
| Metric |
Current Value |
Source |
Notes |
| Time to create + submit SEF invoice (manual) |
45-90 minutes |
User research |
Includes portal navigation |
| Time to create + submit SEF invoice (Bilko target) |
< 5 minutes |
Product target |
Wizard + auto-submit |
| Monthly software cost for compliant accounting |
€100-200+ (Pantheon) |
Market research |
For Serbian SMB |
| Bilko target price |
€8-25/month |
Pricing model |
4-20× cheaper than incumbents |
| SMBs currently non-compliant with SEF |
~60% of eligible |
APR estimates |
Regulatory enforcement risk |
4. Future State Vision (TO-BE)
4.1 Future State Description
With Bilko, a Serbian SMB owner opens their browser, creates a compliant e-invoice in under 5 minutes (including line items, PDV, multi-currency), and submits it directly to SEF without touching the government portal. Expenses are categorized automatically. Bank statements are imported via CSV and matched to transactions. At month end, the PDV report is generated in one click and exported in the format required by Poreska Uprava. The owner has real-time P&L, cash flow, and balance sheet visibility from any device.
4.2 TO-BE Process Flow
flowchart LR
A([SMB Owner]) --> B[Open Bilko — Create Invoice]
B --> C[Select client, add items, auto-PDV]
C --> D[One-click: Email PDF + submit to SEF]
D --> E[SEF confirms — status updated in Bilko]
E --> F[Invoice marked Sent/Paid automatically]
F --> G[Double-entry transaction auto-created]
G --> H[Dashboard updates P&L + cash flow]
H --> I[Month end: 1-click PDV report export]
I --> J([Owner files PDV in < 10 minutes])
4.3 Key Improvements
| Area |
AS-IS |
TO-BE |
Improvement |
| Time to create + submit SEF invoice |
45-90 min |
< 5 min |
90% time reduction |
| Monthly accounting software cost |
€100-200+ |
€8-25 |
4-20× cheaper |
| Real-time financial visibility |
Monthly (accountant) |
Instant |
Continuous |
| SEF compliance rate |
~40% (market average) |
100% for Bilko users |
Compliance guaranteed |
| PDV report preparation |
2-4 hours/month |
< 10 minutes |
95% time reduction |
5. Market Analysis & Competitive Landscape
5.1 Market Context
The Balkan region has 348,000+ active SMBs across Serbia (300K+), Croatia (140K+), and Bosnia-Herzegovina (~80K VAT-registered). The 2023 Serbian SEF mandate and January 2026 Croatian eRačun mandate create regulatory forcing functions that are driving digital adoption at a pace not seen since SEPA in Western Europe. The €50-150M TAM is currently served by legacy ERP vendors (Pantheon, Minimax) who have not modernized their UX or pricing to match the SMB segment.
5.2 Competitive Analysis
| Competitor |
Solution Type |
Key Features |
Pricing |
Our Advantage |
| Pantheon |
ERP (direct) |
Full accounting, SEF, inventory, payroll |
€150-300+/month |
Bilko is 6-20× cheaper; Fiken-simple UX; cloud-native |
| Minimax |
Accounting SaaS (direct) |
Invoicing, accounting, SEF support |
€50-100/month |
Bilko has better UX; lower price; modern stack |
| QuickBooks |
Global SaaS (indirect) |
Full accounting, mobile, 700+ integrations |
€30-50/month |
Bilko has SEF/eRačun; local language; local currency |
| Xero |
Global SaaS (indirect) |
Full accounting, bank feeds, multi-currency |
€35-55/month |
Bilko has Balkan compliance; cheaper for basic use |
| Manual + Excel |
Substitute (indirect) |
Free |
Free |
Bilko is affordable + compliant; fines avoided |
5.3 Positioning
Unique Value Proposition: The only cloud accounting software built for Balkan SMBs — with local language, local tax compliance (SEF, eRačun, PDV), and Fiken-level UX simplicity at €8-25/month.
Target Market: Serbian SMBs (Phase 1) → Croatian SMBs (Phase 2) → BiH SMBs (Phase 3)
Differentiators: Local compliance out-of-the-box · Native languages · Affordable SaaS model · Modern cloud UX · Double-entry with Balkan Chart of Accounts
6. Stakeholder Needs Analysis
| Stakeholder Group |
Primary Needs |
Secondary Needs |
Pain Points Addressed |
Priority |
| SMB Owner (non-accountant) |
Create SEF invoices fast; see P&L; file PDV easily |
Mobile access; expense receipts; client management |
PP-01, PP-02, PP-03, PP-05 |
High |
| Bookkeeper / Accountant |
Manage multiple client orgs; export VAT reports; double-entry accuracy |
Client collaboration tools; bulk operations |
PP-04, PP-05 |
High |
| Import/export business |
Multi-currency invoices (EUR, BAM, RSD); exchange rate locking |
Currency reports; consolidated P&L in base currency |
PP-06 |
Medium |
| Tech-savvy early adopter |
REST API; webhook notifications; data export |
CSV/JSON export; OAuth integration |
— |
Low |
7. Business Requirements
| ID |
Requirement |
Description |
Priority |
Rationale |
Source |
BO Reference |
| BR-001 |
SEF e-invoice submission |
System must create, sign, and submit e-invoices to efaktura.gov.rs (SEF) in UBL 2.1 format |
Must Have |
Serbia launch blocker; legal requirement since 2023 |
Regulatory research + APR |
BO-01 |
| BR-002 |
PDV auto-calculation (Serbia) |
System auto-calculates 20% standard and 10% reduced PDV on all invoice line items |
Must Have |
Core tax compliance; manual calculation error-prone |
Regulatory research |
BO-01 |
| BR-003 |
Double-entry bookkeeping |
Every financial event generates a balanced debit + credit entry per Balkan GAAP standards |
Must Have |
Required for legal compliance and Balance Sheet accuracy |
Accounting law |
BO-01 |
| BR-004 |
Multi-currency support |
System handles BAM, RSD, EUR, USD with exchange rate locking at transaction date |
Must Have |
Balkan businesses transact in multiple currencies |
User research |
BO-01, BO-02 |
| BR-005 |
Bank statement import |
System accepts CSV uploads from Serbian banks for transaction reconciliation |
Must Have |
Live bank API not available in Phase 1; manual reconciliation is blocking pain |
User research |
BO-02 |
| BR-006 |
Financial reports |
System generates P&L, Balance Sheet, Cash Flow Statement, and VAT/PDV report |
Must Have |
Required for business owners and accountants; PDV report needed for monthly filing |
User research |
BO-03 |
| BR-007 |
Multi-user collaboration with RBAC |
Organizations can invite multiple users with roles: Owner, Admin, Accountant, Viewer |
Must Have |
Accountants need access to client orgs; business owners need to control what accountants see |
User research |
BO-02, BO-03 |
| BR-008 |
PDF invoice generation + email delivery |
System generates professional PDF invoices with Bilko/client branding and delivers via email |
Must Have |
Standard B2B invoicing requirement |
User research |
BO-02 |
| BR-009 |
Expense tracking |
System records expenses with category, amount, payment method, and receipt photo |
Must Have |
Core accounting requirement; feeds P&L and cash flow |
User research |
BO-02 |
| BR-010 |
Chart of Accounts (Balkan GAAP) |
System provides pre-populated Serbian/Balkan Chart of Accounts per Pravilnik 2021 |
Must Have |
Required for legal compliance and proper financial reporting |
Regulatory research |
BO-01 |
| BR-011 |
Serbian language support |
All UI, invoices, and reports available in Serbian (Latin and Cyrillic) |
Must Have |
Target market speaks Serbian; global tools fail here |
User research |
BO-02 |
| BR-012 |
Immutable audit trail |
System logs all financial actions with user, timestamp, before/after values; append-only |
Must Have |
Required by Serbian accounting law; non-negotiable |
Regulatory research |
BO-01 |
| BR-013 |
Data export (GDPR-aligned) |
Users can export all their organization's data in machine-readable format |
Must Have |
GDPR Article 20 portability; user trust |
Legal |
BO-01 |
| BR-014 |
Secure multi-tenancy |
Each organization's data is completely isolated; no cross-tenant data access |
Must Have |
Financial data confidentiality; SaaS security baseline |
Security |
BO-01 |
| BR-015 |
Croatian eRačun integration |
System submits e-invoices to HR-FISK (FINA) in Croatian format |
Should Have |
Croatia Phase 2; eRačun mandatory Jan 2026 |
Regulatory research |
BO-04 |
| BR-016 |
Bosnian/Croatian language support |
Full UI and invoice support in Bosnian and Croatian |
Should Have |
Phase 2 expansion markets |
User research |
BO-04 |
| BR-017 |
AI-assisted bookkeeping |
System suggests expense categories and transaction classifications |
Could Have |
Reduces manual entry; competitive differentiator |
Market research |
BO-05 |
| BR-018 |
Payroll management |
Track employee salaries, generate payroll documents |
Won't Have (Phase 1) |
Complexity high; Phase 2 feature |
Strategic decision |
— |
8. Success Metrics & KPIs
| ID |
KPI |
Category |
Baseline |
Target |
Measurement Method |
Evaluation Date |
Owner |
| KPI-01 |
Paying organizations |
Revenue |
0 |
100 orgs by Day 90 |
Billing system |
90 days post-launch |
John |
| KPI-02 |
Monthly Recurring Revenue |
Revenue |
€0 |
€500 MRR by Month 3 |
Billing system |
3 months post-launch |
Alem |
| KPI-03 |
Activation rate |
Adoption |
0% |
≥ 80% create invoice in 7 days |
Analytics |
Monthly |
John |
| KPI-04 |
Monthly churn |
Retention |
N/A |
≤ 5%/month |
Billing system |
Monthly |
John |
| KPI-05 |
NPS score |
Satisfaction |
N/A |
≥ 50 |
In-app survey |
60 days post-launch |
John |
| KPI-06 |
SEF submission success rate |
Compliance |
N/A |
100% |
SEF API response logs |
Launch day + ongoing |
John |
| KPI-07 |
System uptime |
Reliability |
N/A |
≥ 99.9% monthly |
Monitoring |
Ongoing |
John |
| KPI-08 |
Page load time (subsequent) |
Performance |
N/A |
< 1 second p95 |
Lighthouse + monitoring |
Launch + 30 days |
John |
| KPI-09 |
Time to create first invoice |
UX |
45-90 min (incumbent) |
< 5 minutes in Bilko |
In-app analytics |
Post-launch |
John |
9. Business Rules & Constraints
9.1 Business Rules
| ID |
Rule |
Category |
Source |
Enforced By |
| RUL-01 |
All monetary amounts stored as NUMERIC(19,4) — NEVER float |
Financial |
Internal engineering standard |
Database schema + Prisma |
| RUL-02 |
Every financial transaction must generate balanced debit + credit entries |
Financial |
Serbian Accounting Law |
Application layer + DB constraint |
| RUL-03 |
Exchange rate locked at transaction date — cannot be edited retroactively |
Financial |
Accounting standards (IFRS) |
Database immutability + LoggedAction |
| RUL-04 |
LoggedAction table is append-only — no deletes, no updates |
Legal/Audit |
Serbian accounting law (document retention) |
Database constraint + application |
| RUL-05 |
SEF invoice numbers must follow Serbian sequential numbering format |
Legal |
APR / SEF specification |
Invoice numbering service |
| RUL-06 |
PDV rate applied based on organization's country + product/service category |
Tax |
Serbian Tax Law (Zakon o PDV) |
VAT calculation engine |
| RUL-07 |
Financial data must be retained for minimum 10 years (Serbia), 11 years (Croatia) |
Legal |
Local accounting laws |
Data retention policy |
| RUL-08 |
Organizational data is strictly scoped — no cross-tenant queries permitted |
Security |
Multi-tenancy design |
Organization-scoped middleware |
9.2 Regulatory & Compliance Requirements
| Regulation |
Applicability |
Requirements |
Responsible |
| Zakon o elektronskom fakturisanju (Serbia) |
Yes — mandatory B2B since 2023 |
SEF e-invoice submission; UBL 2.1 XML; digital signatures |
John (Tech Lead) |
| Zakon o PDV (Serbia) |
Yes |
20% standard, 10% reduced PDV; monthly filing by 15th |
John + Asmir |
| Zakon o računovodstvu (Serbia) |
Yes |
Double-entry; 10-year document retention; annual balance sheet |
John + Asmir |
| GDPR (EU-adjacent) |
Yes — applies to data of EU citizens and ALAI Holding AS (Norway) |
Data minimization, right to deletion, DPA, 72h breach notification |
John + Alem |
| Croatian Zakon o fiskalizaciji (Phase 2) |
Future |
eRačun (HR-FISK/FINA) submission; 25% VAT; 11-year retention |
Phase 2 |
| BiH PDV regulations (Phase 3) |
Future |
17% PDV; CPF e-invoice (expected 2027) |
Phase 3 |
9.3 Technical Constraints
- Must integrate with: SEF API (efaktura.gov.rs) — REST/UBL 2.1
- Must support: Chrome 100+, Firefox 100+, Safari 16+, Edge 100+ (desktop + mobile)
- Must run on: Cloud infrastructure (no on-premises requirement)
- All monetary arithmetic: NUMERIC(19,4) — no float/number types for currency
- Monorepo structure: Turborepo — cannot deviate from established Next.js + Express stack without ADR
- Database: PostgreSQL via Prisma — no ORM substitution
10. Assumptions & Dependencies
10.1 Assumptions
| # |
Assumption |
Risk if False |
Validation Owner |
| A-01 |
SEF API (efaktura.gov.rs) sandbox is available for development testing |
Integration delayed 4-6 weeks |
John / Asmir |
| A-02 |
No software certification required by Serbian tax authority for MVP launch |
Compliance blocker; launch delayed |
Asmir (legal research) |
| A-03 |
UBL 2.1 XML format accepted by SEF for all invoice types in Phase 1 |
Invoice engine rework required |
John |
| A-04 |
€11-17K budget sufficient for Phase 1 MVP |
Scope reduction required |
Alem + John |
| A-05 |
Beta testers (5 SMBs + 3 accountants) can be recruited through Asmir's network |
Beta delayed; less feedback |
John + Asmir |
10.2 Dependencies
| # |
Dependency |
Type |
Impact if Unavailable |
Target Date |
Status |
| DEP-01 |
SEF API sandbox access credentials |
External (APR) |
Cannot develop/test e-invoicing |
2026-03-01 |
Pending |
| DEP-02 |
ALAI Tech d.o.o. Serbia registration |
External (government) |
Cannot legally operate in Serbia |
2026-04-01 |
In progress |
| DEP-03 |
Exchange rate API selection (ECB / fixer.io) |
Internal decision |
Multi-currency features incomplete |
2026-03-07 |
Open |
| DEP-04 |
Beta tester recruitment |
External |
Beta phase delayed |
2026-03-28 |
Open |
| DEP-05 |
bilko.rs + bilko.io domain SSL setup |
External (registrar) |
Cannot launch production |
2026-04-14 |
Open |
11. ROI Analysis / Cost-Benefit
11.1 Investment Summary
| Cost Category |
One-Time (EUR) |
Annual (EUR) |
Notes |
| Development (Phase 1) |
€12,000 |
— |
Includes backend + frontend + DevOps |
| Infrastructure (Year 1) |
€1,200 |
€1,200 |
Cloud hosting, CDN, monitoring |
| Third-party APIs + services |
€800 |
€500 |
SEF, exchange rate, email |
| Design + branding |
€1,500 |
— |
Landing page, invoice templates |
| Total Year 1 |
€15,500 |
€1,700 |
Within €17K ceiling |
11.2 Benefit Projections
| Benefit |
Year 1 (EUR) |
Year 2 (EUR) |
Year 3 (EUR) |
Confidence |
| SaaS subscription revenue (Serbia) |
€18,000 |
€42,000 |
€72,000 |
Medium |
| Additional revenue (Croatia + BiH) |
— |
€15,000 |
€45,000 |
Low |
| Total Revenue |
€18,000 |
€57,000 |
€117,000 |
Medium |
11.3 ROI Summary
| Metric |
Value |
| Total Phase 1 Investment |
€17,000 |
| Net Benefit Year 1 |
€18,000 - €1,700 = €16,300 |
| Payback Period |
~12-14 months (post-launch) |
| 3-Year ROI |
~800% |
| 3-Year NPV (discount rate: 10%) |
~€140,000 |
12. Implementation Roadmap
| Phase |
Description |
Key Deliverables |
Duration |
Success Criteria |
| Phase 1 — Serbia MVP |
Core accounting + SEF e-invoicing |
50 API endpoints, 8 frontend modules, SEF integration |
10 weeks |
100 paying orgs in 90 days; 100% SEF success rate |
| Phase 2 — Croatia |
eRačun integration + HR-FISK |
Croatian locale, 25% VAT, eRačun submission |
8 weeks |
Croatia beta by Q4 2026 |
| Phase 3 — BiH |
BiH PDV + CPF (when available) |
Bosnian locale, 17% PDV, CPF integration |
6 weeks |
BiH beta by Q2 2027 |
| Phase 4 — Enhancement |
Payroll, AI bookkeeping, API |
Payroll module, AI suggestions, public API |
Ongoing |
Reduce churn; increase ARPU |
13. Risk Assessment
| # |
Risk |
Probability |
Business Impact |
Mitigation |
| BR-R01 |
SEF API instability at launch |
Medium |
Critical — users cannot submit invoices |
Abstract behind service layer; fallback to manual submission instructions |
| BR-R02 |
Serbian regulatory changes pre-launch |
Low |
High — compliance requirements change |
Asmir monitors APR; 2-week buffer in timeline for regulatory updates |
| BR-R03 |
Pricing underestimation — SMBs won't pay even €8/month |
Low |
High — entire business model at risk |
Beta price testing; free tier with conversion; Freemium model as backup |
| BR-R04 |
Pantheon launches competitive cloud product |
Low |
Medium — reduces TAM addressable |
Bilko wins on UX simplicity and price; switching costs are low but brand loyalty builds |
| BR-R05 |
Currency volatility (RSD depreciation) |
Medium |
Low — affects EUR pricing attractiveness |
Price in EUR; local currency display only |
Full technical risk register: ../governance/RISK-REGISTER.md
Approval
| Role |
Name |
Date |
Signature |
| Author |
John (AI Director) |
2026-02-23 |
|
| Reviewer |
|
|
|
| Business Analyst |
John |
2026-02-23 |
|
| Product Owner |
John |
2026-02-23 |
|
| AI Director (John) |
John |
2026-02-23 |
|
| Client Sponsor |
N/A — internal product |
— |
|
| CEO (Alem) |
Alem Bašić |
|
|
