# Tax Code Quality Indicators

> Quality indicator codes returned by Egon Tax Code services when calculating, extracting, checking, and matching Italian tax codes.

Reference codes returned for tax-code calculation, extraction, checking, and matching in Egon Tax Code services.

## Quality Codes

Detailed quality indicators describing checksum calculations, birth coherence, omocody substitution, and national identifier consistency.

| Flag | Code | Description |
| --- | --- | --- |
| 0 (OK) | 0 | OK |
| 1 (Changed) | 901 | Date of birth not present |
| 1 (Changed) | 902 | Gender not present |
| 1 (Changed) | 903 | Different tax code due to omocodia (digits replaced by letters) |
| 1 (Changed) | 904 | Ambiguous characters |
| 1 (Changed) | 905 | Uppercase characters |
| 1 (Changed) | 906 | Double name |
| 1 (Changed) | 907 | Double surname |
| 1 (Changed) | 908 | Inverted name and surname |
| 1 (Changed) | 909 | Inverted VAT number and tax code |
| 1 (Changed) | 998 | Logic error |
| 1 (Changed) | 999 | Not processed |
| 2/3 (Not valid) | 401 | Code not present |
| 2/3 (Not valid) | 402 | Wrong format |
| 2/3 (Not valid) | 403 | Wrong code |
| 2/3 (Not valid) | 404 | Not numerical |
| 2/3 (Not valid) | 405 | Code too long |
| 2/3 (Not valid) | 406 | Wrong date of birth |
| 2/3 (Not valid) | 407 | Incongruent date of birth |
| 2/3 (Not valid) | 408 | Incongruent gender |
| 2/3 (Not valid) | 409 | Wrong tax office code |
| 2/3 (Not valid) | 410 | Incongruent tax office code |
| 2/3 (Not valid) | 411 | Incongruent National Identifier |
| 2/3 (Not valid) | 412 | Incongruent VAT number |
| 2/3 (Not valid) | 413 | Surname not present |
| 2/3 (Not valid) | 414 | Name not present |
| 2/3 (Not valid) | 415 | Date of birth not present |
| 2/3 (Not valid) | 416 | Gender not present |
| 2/3 (Not valid) | 417 | Place of birth not present |
| 2/3 (Not valid) | 418 | Wrong check-digit |
| 2/3 (Not valid) | 419 | Wrong surname |
| 2/3 (Not valid) | 420 | Wrong name |
| 2/3 (Not valid) | 421 | Wrong place of birth |
| 2/3 (Not valid) | 422 | Inconsistent surname |
| 2/3 (Not valid) | 423 | Inconsistent name |
| 2/3 (Not valid) | 424 | Wrong month of birth |
| 2/3 (Not valid) | 425 | Wrong day of birth |
| 2/3 (Not valid) | 426 | Wrong gender |
| 2/3 (Not valid) | 427 | Place of birth not found |
| 2/3 (Not valid) | 428 | Invalid data |
| 2/3 (Not valid) | 429 | Year of birth not numerical |
| 2/3 (Not valid) | 430 | Month of birth not numerical |
| 2/3 (Not valid) | 431 | Day of birth not numerical |
| 2/3 (Not valid) | 432 | Ambiguous place of birth |
| 2/3 (Not valid) | 433 | Incongruent place of birth |
| 2/3 (Not valid) | 434 | Double name |
| 2/3 (Not valid) | 435 | Double surname |
| 2/3 (Not valid) | 436 | Cadastral code not found |
| 2/3 (Not valid) | 437 | Province code not found |
| 2/3 (Not valid) | 438 | Wrong VAT number |
| 2/3 (Not valid) | 439 | Not numerical VAT number |
| 2/3 (Not valid) | 440 | VAT number not present |
| 2/3 (Not valid) | 441 | Mandatory data not present |
| 2/3 (Not valid) | 444 | Tax code not present |
| 2/3 (Not valid) | 445 | Economy activity code not found |
| 2/3 (Not valid) | 446 | Old economy activity code not found |
| 2/3 (Not valid) | 447 | VAT number in the tax code field |
| 2/3 (Not valid) | 448 | Tax code in the VAT number field |
| 2/3 (Not valid) | 449 | Wrong tax office code |