phone number format libphonenumber invalid region code error

Fix libphonenumber invalid region code error

TL;DR

The region code must be an uppercase ISO 3166 two-letter code, so normalize it before parsing. Lowercase, three-letter, or full country names all fail validation. Uppercase the code and validate it against the ISO list, then parse.

The error

Error: Invalid region code: "usa"
libphonenumber parse rejects the region

Fix it

Step 1: Reproduce with the failing value

node -e "const {parsePhoneNumberFromString}=require('libphonenumber-js'); console.log(parsePhoneNumberFromString('+15551234567','usa'))"

Expected: You see the invalid region error or a null result.

Step 2: Normalize to uppercase two-letter codes

node -e "const fix=r=>String(r).trim().toUpperCase().slice(0,2); console.log(fix('usa'), fix(' us '))"

Expected: usa becomes US, with a note that truncation is a stopgap not a mapping.

Step 3: Map names to codes properly instead of truncating

node -e "console.log('keep a name to code map for inputs like united states to US, do not slice names')"

Expected: Real mapping replaces the hack.

Step 4: Parse again and confirm

node -e "const {parsePhoneNumberFromString}=require('libphonenumber-js'); const p=parsePhoneNumberFromString('+15551234567','US'); console.log(p.isValid(), p.formatInternational())"

Expected: The number parses and validates.

When to use this

• libphonenumber rejects the region code
• Region codes come from user input or a CMS

When NOT to use this

• The region is valid but the number is invalid, check the number
• You parse without a region, pass one or use full international format

Tool and version compatibility

• libphonenumber-js, google-libphonenumber
• ISO 3166-1 alpha-2 codes

Variant phrasings

region code with whitespace

Trim before validating. CMS values often carry stray spaces.

three-letter codes in the data

Map alpha-3 to alpha-2 explicitly. Slicing gives the wrong code for many countries.

Why it happens

The library validates the region against the ISO alpha-2 list before parsing. Anything else, lowercase, names, alpha-3, fails fast with the invalid region error instead of guessing.

Edge cases

• Some territories share codes, know which one your data means
• Validate the region once at ingestion, not on every parse
• The error message quotes your input, read it, it usually shows the problem

Provenance

Resolved from the public thread: https://vectle.com/posts/pst__9t9epgKS38n7To6tuZhYw