Normalizes US ZIP codes to either 5-digit ("12345") or ZIP+4 ("12345-6789") format by removing punctuation and whitespace. Postal codes are treated as character strings; leading zeros are preserved.
Usage
normalize_zip(
postal,
format = c("zip5", "zip9", "digits"),
invalid = NA_character_,
strict = TRUE,
na_if_blank = TRUE
)Arguments
- postal
Character vector of postal codes.
- format
Output format: "zip5" (always 5 digits), "zip9" (ZIP+4 when available), or "digits" (raw digits, 5 or 9).
- invalid
Value to return for invalid postal codes.
- strict
Logical; if TRUE, only accept exactly 5 or 9 digits after cleaning. If FALSE, will attempt to salvage by taking the first 5 digits when at least 5 are present, and the first 9 digits when at least 9 are present.
- na_if_blank
Logical; if TRUE, blank/whitespace-only inputs become
invalid.
See also
Other normalization:
normalize_phone()
Examples
zips <- c("12345", "12345-6789", "12345 6789", " 12345 ")
# Default 5-digit format
normalize_zip(zips)
#> [1] "12345" "12345" "12345" "12345"
# ZIP+4 format (preserves 9-digit codes)
normalize_zip(zips, format = "zip9")
#> [1] "12345" "12345-6789" "12345-6789" "12345"
# Raw digits
normalize_zip(zips, format = "digits")
#> [1] "12345" "123456789" "123456789" "12345"
# Preserve leading zeros
normalize_zip("01234")
#> [1] "01234"