If you’re in the military or know someone who is, you’ll want to read on. Starting October 31, the nationwide credit reporting agencies – Equifax, Experian, and TransUnion – must provide free electronic credit monitoring services to active duty servicemembers serving away from their usual duty station and to National Guard members.

Why might you want this service? A credit monitoring service will track activity on your credit reports at the major credit reporting agencies. It can alert you to mistakes or problems on your credit report that might be the result of identity theft. Credit monitoring is not complete protection against fraud – it only warns you about new activity on your credit report – but with those warnings you can take steps to resolve problems before they spread.

What do I need to do? The nationwide credit reporting agencies are still working out the details on how to sign up.

What happens after I sign up? Once you have the credit monitoring service, the credit reporting agencies must notify you by mobile app, email, or text within 48 hours of any “material additions or modifications” to your credit file. Changes that trigger notification include: material changes of address; changes to negative information in your file (things like payments that are more than 30 days late, bankruptcy information, foreclosures, or liens); changes to credit account limits (of $100 or greater); and new accounts opened in your name, including collection accounts.

The credit reporting agencies may not market other services to you while you are in the enrollment process for electronic credit monitoring.

If you find inaccurate or fraudulent information on your credit report, read Disputing Errors on Your Credit Report. If you find signs of identity theft, visit Identitytheft.gov to get started on recovery.

This post was revised to correct the implementation date.