How to extract invoice number from a string

Hi all,
I have some string please check below:

  1. eref+notprovided SVWZ+SABEN AQUELL . FACT. 1 047215

  2. eref+2024/24fc/143 SVWZ+Abono de su factura 01 047184

  3. eref+notprovided SVWZ+WONKA . FACT. 1047108 . 1047245 . 1047109

  4. eref+notprovided DEBT+B31866551 SVWZ+PAGO FRA 01045354

I want to extract the invoice number. so my output should be below

1 047215
01 047184
1047108 . 1047245 . 1047109

I am trying the below pattern:


but it is working for the first three strings. for last one I could not able to extract the invoice no.

I would need your help and Kindly send one accurate regex pattern.

Thanks in advance.

Hi @roysupriya21

Regex Pattern: (?<=[A-Za-z]+.?)\s+\d+.*


1 Like

Hello @roysupriya21 ,
if you have this 4 string so you can use


Dheerendra Vishwakarma

Hi @roysupriya21

you can use regular expression to extract invoice no from the following strings

System.Text.RegularExpressions.Regex.Match(inputString, “(?<=FACT.|FRA\s)([\d\s.]+)|(\b\d{2}\s\d+)”).Value.Trim()


  • (?<=FACT\.|FRA\s): Positive lookbehind to match either “FACT.” or "FRA " without including them in the match.
  • ([\d\s.]+): Matches one or more digits, spaces, or dots.
  • |: OR operator.
  • (\b\d{2}\s\d+): Matches two digits followed by a space and more digits, indicating an invoice number in the format “01 047184”.