Constant spam calls: block and filter them on iPhone and Android

What can a call filter actually do?

Most nuisance calls are either marketing you never agreed to or attempts at fraud. In both cases the number on your screen may not be real. Germany's telecoms regulator, the Bundesnetzagentur, explains that callers can fake the number they display without owning it, a technique known as caller ID spoofing. They may use real numbers belonging to uninvolved people or numbers that do not exist.

Filters therefore work at two levels: your phone sorts calls by contacts, spam detection and numbers you block, while networks hide or block suspicious calls, such as calls from abroad showing a national number. Switzerland's State Secretariat for Economic Affairs (SECO) is clear that there is no complete protection, but together the two levels cut down the number of unwanted calls.

Tip: Before you switch a filter on, save the numbers that must always reach you: your GP surgery, your children's school, your employer, a care service. According to Apple, you always see calls from saved contacts.

How do you set up call filtering on an iPhone?

Apple's Phone app offers three tools: screening or silencing unknown callers, sorting missed calls into separate lists and blocking individual numbers.

Worth knowing: on versions earlier than iOS 17, Live Voicemail also needs to be turned on to use call screening. If you call emergency services, call screening is turned off for 24 hours. And while you are roaming, calls are not screened, whatever your settings.

A blocked number can still leave you a voicemail, but you won't get a notification, and the caller is not told about the block.

How do you set up call filtering on Android?

Many Android phones use the Phone app by Google. Google says caller ID and spam protection is on by default there. Filter spam calls is a separate, optional setting.

Filtered calls trigger no missed-call or voicemail notifications but stay in your call history, and voicemail remains available. Google notes that some steps only work on Android 6.0 and up. Phones with automatic Call Screen don't show Filter spam calls, because spam blocking is one of the Call Screen options there. If your phone uses a different phone app, check your phone maker's help pages.

Tip: Thinking of adding a separate call-blocking app? First check who makes it and which permissions it asks for, as described in Installing an app: how to find the right provider.

What does the network do, and where do you report?

Some filtering happens before a call ever reaches your phone, and each country has its own reporting channels. Switzerland is not in the EU and sets its own rules. Report promptly: in Germany, traffic data is usually deleted after seven days.

If a caller pretends to be the police or your bank, or asks you for money, contact the police as well. Save the call log first, for example as a screenshot of your phone's or router's call list. If you have already transferred money, follow Money sent to a scammer: first steps with your bank and the police.

When are sales calls allowed at all?

Rules differ across Europe. Two examples show the range.

France: since 11 August 2026, consent must be active, informed and revocable. A pre-ticked box or silence is not enough. When asking for consent, the company must say who it is, what the calls are for and how long the consent lasts, for a maximum of one year. You can withdraw it at any time, including verbally during a call. Calling someone to obtain consent is itself prohibited.

Spain: since 29 June 2023, a company may call you with offers if you consented beforehand, or if you were its customer and the offer is similar to what you bought, though not once the relationship has ended and a year has passed without contact. Each call must start with the company's name, the commercial purpose and a reminder that you can object.

Tip: To stop calls from a company you once dealt with, say calmly: “I withdraw my consent; please delete my number.” Then note the date, time, number shown and company name. That helps with any later complaint.

An example: Tom gets his evenings back

Fictitious example: Tom, an Irish engineer who lives in Munich, gets several calls a week from numbers he doesn't know. Some offer solar panels, others claim to be about a parcel. One evening his phone shows a Munich landline number, and the caller says Tom's bank account has been compromised.

Tom saves his GP, his son's nursery and his landlord as contacts. In the Phone app by Google, he checks that caller ID and spam is on and turns on Filter spam calls. He hangs up on the supposed bank call and rings his bank on the number printed on his card, as described in Unexpected call from your bank: check independently before you approve anything. The bank confirms it did not call.

Because the Munich number looked genuine, Tom suspects it was faked and reports it that evening via the Bundesnetzagentur's number manipulation form. A week later, most nuisance calls go quietly into his call history.