Home My Training My Union Resolutions Resources Get Help Merch Store
Sign in
Letter Carriers · CCA Basics

Scanner Use

Using the MDD scanner to protect your time, your pay, and your route evaluations.

📱 Using the MDD Scanner: A CCA's Guide

The MDD (Mobile Delivery Device) scanner is one of your most important tools as a City Carrier Assistant (CCA). It tracks your movements, records deliveries, and logs clock rings. Knowing how to use it correctly helps protect your time, your pay, and your route evaluations.

🛠️ Scanner Overview

The MDD scanner performs multiple functions:

  • Tracks parcels and mailpiece delivery (via barcode scans)
  • Captures clock ring events (Begin Tour, Leave to Street, Return to Office, etc.)
  • Records MSP scans (Management Service Points)
  • Provides alerts, messages, and delivery exceptions

⏱️ Clock Ring Functions

Every major action in your day begins or ends with a scanner entry. Use these clock rings as instructed:

  • Begin Tour – Clock in when your shift starts
  • Leave to Street – When you depart for delivery
  • Begin/End Lunch – Use both scans to log unpaid lunch
  • Return to Office – When you return after completing the route
  • End Tour – Final clock ring before you leave for the day

Missed or incorrect clock rings can affect your pay and delivery performance data — double-check before confirming each screen.

📦 Parcel and Mail Delivery Scans

  • Scan all barcoded packages before delivery
  • If unable to deliver, use "Attempted" or "No Access" and leave a PS Form 3849
  • Follow the scanner prompt exactly — it will ask for confirmation and input when needed

📍 MSP Scans

MSP (Management Service Point) scans are fixed points along your route, typically represented by a barcode label on a mailbox or post. When your scanner beeps for an MSP scan:

  • Scan as soon as you reach the designated location
  • If you miss one, report it to your supervisor at the end of the day

Missing MSP scans too often may prompt route scrutiny, even if you delivered correctly.

⚠️ Scanner Alerts and Exceptions

Your scanner may display alerts like:

  • No Access – Gated entry, dog warning, or safety issue
  • Duplicate Scan – Already scanned this item (check for errors)
  • Invalid ZIP – Package may be mis-sorted or not for your route

If in doubt, follow station policy and report the issue before leaving the area. Document problems when necessary on PS Form 1571 or your daily log.

🔋 Scanner Care and Battery Tips

  • Fully charge your scanner before hitting the street
  • Keep it in a holster or weather-resistant case
  • If it dies or malfunctions, notify your supervisor immediately

📚 Related Tools and Forms

  • PS Form 3849: Left when a package can't be delivered
  • PS Form 1571: Records undelivered or curtailed mail
  • Letter Carrier's Daily Log: Good for backing up your scanner data
Final Tip

When used correctly, your scanner is your strongest protection — it logs your time, proves delivery, and shows management that you're doing your job right. Don't let someone else control your data — scan everything, and scan it right.

📝 Test Your Knowledge: MDD Scanner Use Badge

10 questions — 70% to pass, 80% Skilled, 90% Mastered, 100% Perfect.

1. What does the acronym MDD stand for, as used on the page?
2. Which clock ring should a CCA use when departing the office for delivery?
3. According to the page, how should a CCA properly log an unpaid lunch break on the scanner?
4. What does MSP stand for in the context of scanner scans?
5. Per the page, what should a carrier do if they miss an MSP scan?
6. Which scanner alert specifically indicates that a package may be mis-sorted or not intended for your route?
7. Which PS Form is left for the customer when a package can't be delivered?
8. Which PS Form is used to record undelivered or curtailed mail?
9. According to the scanner care and battery tips, what should you do before hitting the street each day?
10. Per the page, what can happen if a carrier misses MSP scans too often, even if deliveries were completed correctly?