Show commas when combining number + text

You might have a currency or number field you want to display with thousands separators even after concatenating with other text (for example a currency code). Airtable's number formatting disappears once a value becomes a text string in a formula, so you need to format it yourself.

Below are two drop‑in formulas you can adapt. They use REGEX_REPLACE to inject commas and handle edge cases.

Integer amounts

Use this when you don’t need decimals:

REGEX_REPLACE(
  REGEX_REPLACE(
    REGEX_REPLACE(
      REGEX_REPLACE(
        REGEX_REPLACE(
          REGEX_REPLACE(
            ROUND({Amount}) & "",
            "(\\d{3})$",
            ",$1"
          ),
          "(\\d*)(\\d{3}),",
          "$1,$2,"
        ),
        "(\\d{1,3})(\\d{3}),",
        ",$1,$2,"
      ),
      "(\\d{1,3}),(\\d{3}),",
      "$1,$2,"
    ),
    "^(\\d{1,3})(\\d{3}),",
    "$1,$2,"
  ),
  "^,",
  ""
) & " " & {asking-currency}

Example result: 12,345 USD

Amounts with two decimals

Keep two decimal places while still adding commas:

IF(
  {Amount},
  REGEX_REPLACE(
    REGEX_REPLACE(
      REGEX_REPLACE(
        REGEX_REPLACE(
          REGEX_REPLACE(
            REGEX_REPLACE(
              ROUNDDOWN({Amount}, 0) & "",
              "(\\d{3})$",
              ",$1"
            ),
            "(\\d*)(\\d{3}),",
            "$1,$2,"
          ),
          "(\\d{1,3})(\\d{3}),",
          ",$1,$2,"
        ),
        "(\\d{1,3}),(\\d{3}),",
        "$1,$2,"
      ),
      "^(\\d{1,3})(\\d{3}),",
      "$1,$2,"
    ),
    "^,",
    ""
  )
  & "."
  & LEFT((ROUND({Amount}, 2) - ROUNDDOWN({Amount}, 0)) * 100 & "0", 2)
  & " " & {asking-currency}
)

Example result: 12,345.67 USD

Common variations

Add a currency symbol: Replace the trailing currency code with a leading symbol:
- "$" & <formatted-number> or "€" & <formatted-number>
Conditional message for zero: Wrap in an IF() to output explanatory text when zero:

IF(
  {Amount} = 0,
  "See request details",
  "$" & <formatted-number-with-commas-and-two-decimals>
)

Replace <formatted-number-with-commas-and-two-decimals> with the full expression from the previous section without the currency code.

Why this works

Once you concatenate a number with text, Airtable turns it into a string and no longer applies numeric display formatting. The nested REGEX_REPLACE calls insert commas every three digits from the right, then a small piece appends the two‑digit decimal part.

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Source and further reading

Community discussion with the original approach and decimal variant: Number Separator in formula field with a text

Airtable: Thousands Separator in a Formula Concatenated with Text