Reply To: Adding spaces to large figures ? with GREP?

Thanks Justin. I am just a beginner. I checked both the expressions (given below), both are working fine even if the numbers are at the end of a paragraph with or without a period. I tested it both way i.e. with paragraph style and with Find/Change.

Here is the text I was using for testing purpose:
ABC is a US-owned company with over 40 years 12345678 experience in the creative industries. We provide 12345 mission critical, creative production services to 123456 newspaper and magazine publishers, 123456 corporations, catalogue retailers, SME?s, packag 123456789 and 1234567890 pre-media companies 123456789.

Find:
(\d\d\d)(?=\d)

Replace:
$0

and

Find:
\d(?=(\d\d\d)+\D)

Replace:
$0 or character style