Las Marias, PR — rate center

NANPA rate center & CO code data, current as of July 28, 2026.

The Las Marias rate center (Puerto Rico) anchors 2 active prefixes under area codes 787, 939. Rate centers, not city limits, are what phone numbers are legally tied to.

2 central-office prefixes are currently anchored to this rate center across 2 carriers. 2 prefixes participate in thousands-block pooling, so blocks of 1,000 numbers are shared between carriers.

Routing-wise it sits in LATA 820.

Multiple area codes over one rate center (787/939) is the overlay pattern: same geography, different first three digits.

With only 2 prefixes, Las Marias sits at the small end of Puerto Rico's rate centers — a handful of carrier blocks cover the whole locality, and a number from here is a fairly strong locality signal (before porting is considered).

Treat this data as geography of the number, not of the caller: porting, VoIP and caller-ID spoofing all detach the two. When a call matters, hang up and call back through an official number.

Prefixes anchored to Las Marias

FAQ

What area code is Las Marias, PR?

Las Marias is served by 2 area codes — 787, 939 — which overlay the same territory.

How many prefixes does Las Marias have?

2 active NXX prefixes are anchored to this rate center in NANPA records, held by 2 carriers.

Is a call from a Las Marias prefix really from Las Marias?

Not necessarily. The prefix marks where the number block was issued; porting, VoIP and spoofing all detach calls from that geography.