TL;DR: Waterfall enrichment is the right way to find European mobiles. Stack several providers and pay only when one finds a number. Many providers resell the same numbers, so each extra one adds less than you think. And the hit rate counts numbers found, while your reps need people who pick up. Check every number before your team dials.
85% found.
That is what our waterfall enrichment run said on a list of 461 senior IT and security contacts in the Netherlands, Belgium and Luxembourg. Eight providers ran one after another and found a usable mobile for 392 people.
It looks like a win. But a found number is no promise of a conversation. A rep dials and reaches a spa instead of an executive. Or the wife of a head of department. Or someone who retired 10 or 15 years ago.
Answrd is part of Profitbl, which runs cold calling campaigns across Europe. We love waterfalls. Here is how to build one for European mobiles, and the one step after it that decides whether your reps talk to anyone.
What is waterfall enrichment for phone numbers?
Waterfall enrichment finds contact data by asking several providers in a fixed order. If the first provider finds no mobile, the contact drops to the second, then the third, until one finds a number. Most waterfall tools charge only when a provider finds something. No single database covers every country, so each step fills the gaps of the one before.
You can buy a waterfall ready-made. Clay says its waterfall gives you access to "150+ databases to maximize your coverage" and that you "pay for what you find" (as of October 2026). FullEnrich says it aggregates contact info from "20+ premium vendors" (as of October 2026).
Or you build your own. We built ours in Claude Code, so we control the order, the rules and the cost per number.
Is waterfall enrichment worth it?
Waterfall enrichment is worth it for any team that calls European decision makers, because one provider alone leaves too many gaps. Our eight-provider waterfall found a usable mobile for 85% of a senior Benelux list.
Cheap data shows the gap fast. A tier of five low-cost providers found usable numbers for 3 of 71 senior security contacts in Germany, Austria and Switzerland, about 4%. Most of what they returned were US numbers for people based in the US.
On a Dutch and Belgian list, a seven-provider cheap tier found 3 of 19 senior security mobiles. Then one specialist provider in our waterfall found 14 of 15.
So the order of providers matters as much as the count.
Why does each extra provider add less than you think?
Each extra provider adds less because many providers buy from the same wholesalers. When two providers resell the same source, the second one finds the same mobile the first one found, or misses the same people. You pay for a fifth step that mostly repeats the first four.
That is fine when a step charges only on hits. It hurts when you pay per lookup. Count the new usable numbers each provider adds after the ones above it. Drop the steps that add nothing for your countries. Keep the ones that find people the others miss, even if they cost more.
Why does the waterfall enrichment hit rate lie?
The hit rate counts numbers found. Your reps need people who pick up. A waterfall marks a contact as a hit the moment any provider returns a number, whether that number is a landline, a personal mobile, a number in the wrong country or a dead line.
Dead lines are not rare. Of 1,195 B2B mobiles from data providers we checked in October 2026, 58 were not in service, about 5%. That is about 5% of your mobile budget gone before anyone dials.
Here is that gap in our own CRM, on 2,879 mobiles from one provider (October 2026):
- 73% passed basic checks. Right country, a mobile and not a known bad number. About one in four failed before anyone dialled.
- We dialled 1,071 of them. Our teams called that many of the numbers that passed.
- 28% reached the person we wanted. The right person answered on 301 of the 1,071 we dialled. Fewer than one in three.
Most failures were wrong-country numbers and landlines. The weakest countries were Belgium, where 40% passed, Ireland at 45% and Switzerland at 52%.
Billed hits tell the same story. One provider on our Benelux list gave us 27 billed hits and 1 usable own-country mobile. That works out to about $20 per usable number. Most of the hits were foreign mobiles and direct lines.
The personal mobile problem
Personal numbers are the biggest problem in Europe right now. Providers return mobiles from a different country than the person. A Luxembourg contact on a Belgian or French mobile is almost always a cross-border worker's private phone.
On our Benelux waterfall, 20 of the misses had only a mobile from a neighbouring country. We counted those as misses and took them out. A waterfall tool would have counted them as hits.
Calling those numbers costs more than a wasted dial. People get angry about GDPR on the phone, most of all in France and Switzerland. The ICO's guide to the accuracy principle says personal data must be "accurate and, where necessary, kept up to date." A private phone filed as a business number is a hard record to defend.
Coverage and correctness are two different numbers. Your waterfall only measures the first.
How do you build a phone waterfall for Europe?
Build it in six steps. Order your providers by cost per usable number, gate every step with rules, pay only on hits, log the source of each number, measure what each step adds, and check every number before the team dials it. Here is the setup we run on our own campaigns:
- Order providers by cost per usable number. Price per lookup misleads. A cheap lookup that rarely finds a usable mobile can cost more per usable number than a pricier one that often does. Test each on one list and put the cheapest per usable number first.
- Gate every step. A number only stops the waterfall if it passes four rules. It matches the person's country. It is a mobile. It is not on your list of known bad numbers. It is not a mobile from a neighbouring country, which in Europe usually means a personal phone. If a number fails, the contact keeps falling to the next provider.
- Pay only on hits. Use providers and plans that charge when they find a number.
- Log which provider found each number. You need it to drop weak steps and to answer a prospect who asks where you got their number.
- Measure new finds per step. After a few lists, cut any provider that only repeats what the ones above it found.
- Check every number before the team dials. The gates catch the obvious junk. They cannot tell you whether the right person picks up.
In Claude Code, you describe the rules and it writes the API calls. The rules in step 2 matter more than the code.
What should you add to the stack?
Providers to test in a European phone waterfall, in no order:
- Kaspr: a LinkedIn Chrome extension and web app for B2B contact data. We have dialled its numbers on our campaigns.
- Eficia: a phone number enrichment platform. We use it in our own stack.
- FullEnrich: a ready-made waterfall in its own right. You can run it as one step inside yours.
- Lusha: a B2B data provider. We have dialled its numbers on our campaigns.
- Forager: a contact data provider focused on mobile numbers, according to its own site (as of October 2026).
- Wiza: a tool that finds emails and phone numbers, including mobiles, according to its own site (as of October 2026).
- Tomba: a tool to find B2B emails and phone numbers, which says it shows the public sources behind each one (as of October 2026).
Switching from one to another rarely fixes wrong-person calls. Here is why Lusha and Kaspr mobiles reach the wrong person.
What happens when you check the numbers before dialling?
Pickup goes up. Checking sorts the numbers that pick up from the wrong, dead and personal ones, so reps dial a shorter list and talk to more people. From our own campaigns:
- Engineering services campaign: real pickup went from 6% to 17% after verified numbers.
- Security software campaign: 12.8% real pickup, against a history of 2% to 5%.
- One recent list: of 131 numbers checked, 13 were bad. Of the good ones, most reached the right person and the rest reached a named voicemail.
That is the job Answrd does. You upload the numbers your waterfall found. You get back the numbers that pick up, with wrong and dead ones flagged. You pay €0.75 per verified number, with credits that never expire. We never sell data, so we sit at the end of your waterfall and never compete with it.
A line check alone misses personal and job-change numbers, as we show in the limits of HLR lookups. To see what bad numbers cost your team today, try the pickup rate calculator.
Frequently Asked Questions
What is an enrichment waterfall?
An enrichment waterfall sends each contact to several data providers in a set order. If the first finds nothing, the next one tries, until one finds a number or email.
Why does my waterfall find numbers that don't work?
A waterfall counts any returned number as a hit, even a dead, wrong or private one. In one provider's data in our CRM, 28% of dialled mobiles reached the person we wanted (October 2026).
Can I build my own waterfall enrichment?
Yes. You need API keys for each provider, an order, rules for a usable number, and a log of which provider found what. We built ours in Claude Code.
How many providers should a phone waterfall have?
As many as keep adding new usable numbers for your countries. We ran eight on our Benelux list. Track new finds per step and cut the ones that add nothing.
Is it legal to call mobile numbers from a waterfall in Europe?
Rules differ by country, so check local rules before you call. GDPR also asks you to keep personal data accurate. Logging the source of each number and taking out personal mobiles helps with both.
Run the waterfall, then check the numbers
Waterfall enrichment is how you find the most European mobiles. Stack the providers, order them by cost per usable number, gate every step and log every source. Then judge it by how many mobiles reach the right person.
Run your waterfall's output through a check before the next call block. Test 100 numbers free, no card needed. If you would rather talk it through, book a 15-minute call.