Identifier Structure in ImPAI
ImPAI generates internal identifiers — such as the Global Id, Internal Id, and other scheme-specific references — using a unified and structured format. This ensures consistency, traceability, and clarity across all payment services and message flows.
All identifiers created by ImPAI follow the same structural pattern described in this chapter.
Overall Format
Each identifier consists of four structured components, combined into a single, continuous string with a fixed length of 16 characters.
This predictable structure ensures that every identifier remains compact, readable, and uniquely traceable within the ImPAI platform.
The 16-character format also guarantees a large enough namespace to generate unique IDs for at least 10 years, even in high-volume environments. This long-term uniqueness supports strict compliance, auditing, and end-to-end traceability requirements across all payment schemes and internal services.
Example: PAI1500000012345
Component Details
1️⃣ Prefix: PAI
A constant prefix used for all backend-generated identifiers to indicate that the value originates from the ImPAI platform.
Length: 3 characters
2️⃣ Scheme-Specific Identifier
This one-digit code indicates the payment scheme or context:
Length: 1 character
| Scheme | Code |
|---|---|
| SEPA Instant | 1 |
| SEPA Credit Transfer (SCT) | 2 |
| SEPA Direct Debit (SDD) | 3 |
| Swift | 4 |
| Other | 0 |
The scheme code helps categorize and search identifiers quickly in logs and operational dashboards.
3️⃣ Year Indicator
Only the final digit of the current calendar year is included.
Length: 1 character
Examples:
- 2025 →
5 - 2030 →
0
4️⃣ Sequence Number
A strictly increasing counter with 11 digits, padded with leading zeros to ensure consistent length.
Length: 11 characters
Examples:
00000000001
00000052345
00001234567
Length Guarantee
All components together result in a fixed length of 16 characters:
| Component | Length |
|---|---|
Prefix PAI | 3 |
| Scheme Code | 1 |
| Year Digit | 1 |
| Sequence Number | 11 |
| Total | 16 |
This consistent length simplifies validation, parsing, and storage across all modules.