- 0851 is a prefix Telkomsel, meaning number 0851 uses the Telkomsel network.
- 0851 Not tied to a specific region; can be activated and used throughout Indonesia.
- 0851 not a number By.U; By.U and regular Telkomsel use different prefixes and services.
What Card Is 0851? Here's an Explanation of Operators and Regions
Have you ever received a phone call or WhatsApp from number 0851 and immediately thought, “What kind of card is 0851?” Don't worry, you're not alone. Many people are often curious about the origin of this number, especially if they suddenly receive a call from an unknown number.
So, in this article we will discuss in detail what the 0851 card is, is it related to... By.U or not, as well as a list of other number codes you should know to avoid guessing incorrectly. Watch until the end, okay?.
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0851 What Card and Which Area?

So, 0851 is the card prefix code Telkomsel. This means that numbers starting with 0851 use the Telkomsel network, one of the largest operators in Indonesia with extensive signal coverage.
Many people think that the number code always indicates a specific area. In fact, the number 0851 is not tied to a specific area.
You can activate a card with the prefix 0851 anywhere in Indonesia, from Sabang to Merauke, without location restrictions.
However, there's one interesting thing you should know. The three or four digits after 0851 (e.g., 0851-566 or 0851-701) are sometimes used as distribution or initial area codes when the card is first marketed. For example, certain digit combinations can point to Sulawesi, Java, or Sumatra.
However, this system isn't absolute. In today's era of online registration and digital distribution, area codes are no longer particularly relevant.
The 0851 number that was originally sold in Sulawesi may now be active and used in Jakarta or other areas.
So in conclusion, if you ask 0851 what card and which area, the answer is:
- Telkomsel Card
- Not tied to a specific region
- Can be used throughout Indonesia
0851 is not a By.U number

Another question that often arises is, “0851 is By.U’s number, right?” The answer is: no.
Although By.U is on the same network as Telkomsel, the number codes used are different. By.U typically uses prefixes like:
- 0851 is not included in By.U
- By.U use 0851 more often? (this is wrong)
- The By.U prefix is generally 0851? Also not correct
The 0851 number belongs entirely to regular Telkomsel, not a By.U product. So if you receive an 0851 number, don't mistake it for a By.U number.
This distinction is important, especially if you want to check internet packages, customer service, or specific promotions. Regular Telkomsel and By.U have different systems and offers.
Other Number Codes You Should Know

Besides 0851, there are many other number codes in Indonesia that can often be confusing. To help you avoid guessing incorrectly, here are some commonly used operator prefix codes:
Telkomsel
- 0811, 0812, 0813
- 0821, 0822, 0823
- 0851, 0852, 0853
Indosat Ooredoo
- 0814, 0815, 0816
- 0855, 0856, 0857, 0858
XL Axiata
- 0817, 0818, 0819
- 0859, 0877, 0878
Three (3)
- 0895, 0896, 0897, 0898, 0899
Smartfren
- 0881, 0882, 0883, 0884, 0885, 0886, 0887, 0888, 0889
By knowing this list, you can be more vigilant when receiving calls or messages from unknown numbers. At the very least, you'll know which carrier it's from.
Now you're no longer confused about what the 0851 card is. In short:
- 0851 is a Telkomsel card
- Not tied to a particular area
- Not a By.U number
- Can be used throughout Indonesia
Also read:
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We hope this article is helpful and relevant to your search needs. If you're still curious about other number codes, please leave a comment.
