Data Sources & Methodology

Last Updated: October 1, 2025
Data Refresh Status: ✅ Operational

Overview

Transfer Charges aggregates financial data from trusted sources to provide comprehensive fee comparisons. This page details our data sources, collection methods, update frequencies, and quality assurance processes.

1. Blockchain & Cryptocurrency Data

1.1 Primary Data Sources

Ethereum Network

Source: Etherscan.io
API Endpoint: Etherscan API v1
Data Retrieved:
- Gas prices (Gwei)
- Base fee and priority fees
- Network congestion metrics
- Historical gas trends
Update Frequency: Every 2-3 minutes
Coverage: Mainnet

Cardano Network

Source: Cardanoscan.io
API Endpoint: Cardanoscan Public API
Data Retrieved:
- Transaction fees (ADA)
- Network statistics
- Epoch information
Update Frequency: Every 3-5 minutes
Coverage: Mainnet

Multi-Chain Price Data

Primary Source: CoinGecko
API Endpoint: CoinGecko API v3
Data Retrieved:
- Current prices (USD)
- Market capitalization
- 24h trading volume
- Price changes (24h, 7d, 30d)
Update Frequency: Every 2 minutes
Coverage: Top 100 cryptocurrencies

1.2 Additional Blockchain Explorers

Blockchain	Explorer Source	Update Frequency
Bitcoin	Blockchain.com, Mempool.space	5 minutes
Polygon	Polygonscan.com	2-3 minutes
BSC	BscScan.com	2-3 minutes
Arbitrum	Arbiscan.io	2-3 minutes
Optimism	Optimistic.etherscan.io	2-3 minutes
Base	BaseScan.org	2-3 minutes
Avalanche	SnowTrace.io	3-5 minutes
Solana	Solscan.io, Explorer.solana.com	2-3 minutes

1.3 Data Processing Methodology

Gas Fee Calculations

Ethereum Transaction Cost = Gas Units × Gas Price (Gwei) × ETH Price (USD) / 10^9
Standard Transfer = 21,000 gas units
Token Transfer = ~65,000 gas units
Complex Smart Contract = 100,000+ gas units

Network Averages

Calculate median of last 100 blocks
Remove outliers (>3 standard deviations)
Weight recent blocks more heavily
Apply smoothing algorithm for display

1.4 Data Quality Measures

✅ Redundancy: Multiple API endpoints for critical data
✅ Validation: Cross-reference between sources
✅ Fallback: Cached data if APIs unavailable
✅ Monitoring: Real-time API health checks
✅ Alerts: Automatic notification of discrepancies

2. Banking & Wire Transfer Data

2.1 Financial Institutions Covered

Major US Banks Monitored

Bank	Official Source	Last Updated	Next Review
Bank of America	bankofamerica.com	Dec 15, 2024	Jan 15, 2025
JPMorgan Chase	chase.com	Dec 18, 2024	Jan 18, 2025
Wells Fargo	wellsfargo.com	Dec 20, 2024	Jan 20, 2025
Citibank	citi.com	Dec 22, 2024	Jan 22, 2025
U.S. Bank	usbank.com	Dec 10, 2024	Jan 10, 2025
PNC Bank	pnc.com	Dec 12, 2024	Jan 12, 2025
TD Bank	td.com	Dec 14, 2024	Jan 14, 2025

2.2 Fee Types Tracked

Domestic Transfers

ACH transfers (standard/same-day)
Wire transfers (online/branch)
Zelle payments
Internal transfers

International Transfers

SWIFT wire transfers
Foreign exchange margins
Intermediary bank fees
Receiving fees

Additional Fees

Account maintenance
Overdraft charges
Stop payment fees
Returned transfer fees

2.3 Data Collection Process

Manual Research Methodology

1. Primary Sources

Official bank websites
Current fee schedules (PDF)
Account disclosure documents
Customer service verification

2. Verification Process

Cross-check multiple account types
Verify with customer service (when unclear)
Document special conditions
Note promotional rates

3. Update Schedule

Full review: Every 2-4 weeks
Spot checks: Weekly
Major changes: Immediate update
Annual review: January each year

2.4 Data Standardization

Fee Normalization

Convert all fees to USD
Separate base fees from percentages
Identify minimum/maximum amounts
Note special conditions/exemptions

3. Exchange Rate Data

3.1 Sources

Primary: CoinGecko API (crypto/fiat)
Secondary: ExchangeRate-API (fiat/fiat)
Update Frequency: Every 5 minutes
Currencies Covered: USD, EUR, GBP, JPY, CAD, AUD

3.2 Calculations

Cross-rate Calculation = Rate A/USD × USD/Rate B
Includes 0.1% buffer for variations
Does not include bank FX margins (typically 2-4%)

4. Historical Data

4.1 Data Retention

Data Type	Retention Period	Granularity
Blockchain Fees	90 days	5-minute intervals
Crypto Prices	365 days	Hourly
Banking Fees	2 years	Monthly snapshots
Exchange Rates	30 days	Daily

4.2 Aggregation Methods

Hourly: Average of 5-minute samples
Daily: Weighted average (volume-based for crypto)
Weekly: Daily averages
Monthly: Daily averages

5. API Rate Limits & Performance

5.1 Current API Usage

Provider	Calls/Day	Limit	Usage %
Etherscan	28,800	100,000	29%
CoinGecko	43,200	50,000	86%
Cardanoscan	14,400	30,000	48%

5.2 Performance Metrics

Average API Response: 250ms
Data Processing Time: 50ms
Cache Hit Rate: 85%
Uptime (30 days): 99.9%

6. Data Accuracy & Limitations

6.1 Known Limitations

Cryptocurrency Data

2-5 minute delay from real-time
May miss flash spikes/drops
Exchange prices may vary ±2%
Network congestion unpredictable

Banking Data

Manual updates every 2-4 weeks
May not reflect promotional rates
Relationship pricing not included
International fees highly variable

6.2 Accuracy Targets

Crypto Fees: Within 5% of actual
Crypto Prices: Within 1% of major exchanges
Banking Fees: 95% accuracy for standard accounts
Update Delays: <5 minutes for automated data

7. Quality Assurance

7.1 Automated Checks

// Validation Rules
- Price changes >50% trigger manual review
- Missing data points trigger fallback sources
- API errors logged and alerted
- Outlier detection on all metrics

7.2 Manual Reviews

Daily: Spot check random data points
Weekly: Verify banking fee changes
Monthly: Full data audit
Quarterly: Source reliability assessment

8. Data Usage Rights

8.1 API Terms Compliance

✅ Etherscan: Community tier, attribution required
✅ CoinGecko: Free tier, 50k calls/day limit
✅ Cardanoscan: Public API, fair use policy
✅ Bank Data: Publicly available information

8.2 Attribution

All data sources are properly attributed. We do not claim ownership of third-party data.

9. Transparency Commitments

We Promise To:

Clearly label data update times
Show sources for all data points
Disclose delays when they occur
Update promptly when errors found
Maintain history of corrections

We Never:

Manipulate data for any purpose
Favor any platform or institution
Accept payment for data placement
Hide fees or important information
Make predictions or recommendations

10. Future Data Additions

Planned Q1 2025

Layer 2 networks expansion
European bank coverage
Stablecoin transfer costs
DeFi protocol fees

Planned Q2 2025

Asian market banking fees
Credit card crypto purchase fees
P2P platform comparisons
Real-time alerts system

11. Report Data Issues

Found an error or discrepancy? Please let us know:

Email: data@transfercharges.com
Response Time: Within 24 hours

Please Include:

Specific data point in question
Screenshot if possible
Time/date observed
Expected vs actual value

Issue Resolution Process

Acknowledgment within 24 hours
Investigation and verification
Correction if confirmed
Notification of resolution
Public correction log updated

12. Data Access & Export

Current Options

Web Interface: Real-time viewing
Screenshots: Allowed for personal use
Manual Copy: Data tables can be copied

Coming Soon

CSV Export: Download historical data
API Access: Developer endpoints
Webhooks: Real-time notifications
Mobile App: iOS/Android apps

13. Legal & Compliance

Data Protection

No personal data collected from APIs
Public blockchain data only
No transaction tracking
GDPR compliant processing

Disclaimer

All data is for informational purposes only. See our Data Disclaimer for full legal terms.

Last System Check: October 1, 2025, 00:00 UTC

All Systems: ✅ Operational

Next Scheduled Maintenance: October 15, 2025, 02:00-04:00 UTC