NixringBlock a whole number range on iPhone by prefix
Premium-rate lines, shared-cost lines and a spammer working through a block all share a prefix. Blocking them one number at a time is hopeless. Here is how a range rule does it in one entry.
Range rules are part of Nixring Pro. Free to download to try the rest.
The constraint
iOS has no wildcards, so the rule writes them out
Apple's Call Directory takes a sorted list of explicit numbers. There is no pattern syntax, no asterisk, nothing that means everything starting with these digits. A range rule closes that gap by enumerating the range for you.
You give it two things: a prefix in digits, and how many trailing digits to fill in, between 1 and 5. The rule then covers every number from the prefix followed by all zeros to the prefix followed by all nines.
| Trailing digits | Numbers covered | First and last in the range |
|---|---|---|
| 1 | 10 | +49 900 0 to +49 900 9 |
| 2 | 100 | +49 900 00 to +49 900 99 |
| 3 | 1,000 | +49 900 000 to +49 900 999 |
| 4 | 10,000 | +49 900 0000 to +49 900 9999 |
| 5 | 100,000 | +49 900 00000 to +49 900 99999 |
Four trailing digits is the default because it is usually the right size: wide enough to cover a service block, narrow enough that you can still reason about what you just blocked.
Ranges worth a rule
Prefixes that stay put
A rule is only worth writing when the prefix is stable. Regulator-allocated service ranges qualify, because the allocation does not change when an individual operator does.
- +49 900German premium rate. Charged per minute or per call, sometimes at several euros a minute.
- +49 137German televoting and mass call numbers. The range behind competition and phone-in lines.
- +49 180German shared cost service numbers. Often legitimate, so think before you shut the whole block.
Twenty numbers from the first of those ranges, fifteen from the second and fifteen from the third are already in the built-in list, so you get a sample of each without writing anything. A rule turns that sample into the whole range.
Wide rules catch real callers. Plenty of ordinary services sit on shared-cost numbers, including support lines you might actually want to reach you. Before writing a rule over a whole block, put the numbers you rely on into the whitelist. Whitelist entries are removed from the published list before iOS ever sees it, so they beat every rule.
Rules and the whitelist are both part of Nixring Pro.
Ceiling
300,000 entries, then it stops
The app will not publish more than 300,000 generated numbers in total. Rule expansion stops there rather than growing without limit, which keeps the list rebuild quick and keeps it within what iOS accepts. Three rules at five trailing digits each will reach that ceiling on their own, so wide rules are worth spending carefully.
Order matters as well. The built-in list and your own numbers are published first, then rules fill the remaining room. Your explicit numbers are never dropped in favour of a rule.
Questions
Frequently asked
Can I block a whole number range on iPhone?
Not with the Phone app, which blocks one number at a time. Apple's Call Directory API has no wildcards either: it accepts explicit numbers only. A range rule works around that by writing out every number in the range for you and handing the whole set to iOS.
How many numbers does one rule cover?
Between 10 and 100,000. A rule is a prefix plus a count of trailing digits between 1 and 5, so it covers ten to the power of that count. A prefix of +49 900 with 4 trailing digits covers the 10,000 numbers from +49 900 0000 to +49 900 9999.
What happens if a rule catches a number I need?
Put that number on the whitelist. A whitelist entry is applied before anything else and removes the number from the published list, so it beats every rule and every blocklist. Both the whitelist and range rules are part of Nixring Pro.
Is there a limit on how many numbers I can block?
Yes. The app stops at 300,000 generated entries in total, so that rebuilding the list stays fast and stays inside what iOS will accept. Three rules of 100,000 numbers each will reach that ceiling.
Related