Monitor, OR — rate center
- State
- Oregon
- Active prefixes
- 2
- Carriers
- 2
- Pooled prefixes
- 1
- LATA
- 672
- Metro area
- Portland-Vancouver-Hillsboro, OR-WA MSA
Monitor is a telephone rate center in Oregon served by area codes 503, 971. A rate center is the locality the phone industry uses to anchor numbers for billing; every prefix listed below is registered here.
NANPA records show 2 active prefixes here, held by 2 different carriers. Pooling applies to 1 of them — individual thousands-blocks may belong to different companies.
The rate center belongs to the Portland-Vancouver-Hillsboro, OR-WA Metropolitan Statistical Area. Routing-wise it sits in LATA 672.
Because 503, 971 all serve this territory, two Monitor numbers can look completely different while being neighbors — check the prefix, not just the area code.
Monitor is a small rate center: 2 prefixes across 2 carriers serve it. Small localities like this often keep the same blocks for decades, so the prefix-to-place mapping tends to be stable.
As always with US numbering: a prefix anchored to Monitor tells you where the block was issued. The person calling may have ported the number, moved away, or be spoofing it entirely — verify callers through independently found contact details.
Prefixes anchored to Monitor
| Prefix | Code holder | Pooled |
|---|---|---|
| 503-634 | MONITOR COOP. TEL. CO. | No |
FAQ
What area code is Monitor, OR?
Monitor is served by 2 area codes — 503, 971 — which overlay the same territory.
How many prefixes does Monitor have?
2 active NXX prefixes are anchored to this rate center in NANPA records, held by 2 carriers.
Is a call from a Monitor prefix really from Monitor?
Not necessarily. The prefix marks where the number block was issued; porting, VoIP and spoofing all detach calls from that geography.