Boku, Fonix, Payforit and Zimpler: Pay by Mobile Explained

What carrier billing actually is

Pay by mobile is direct carrier billing, which is a plain way of saying the deposit goes on your phone bill. On a monthly contract the charge lands on your next statement. On pay-as-you-go it comes straight off the credit already loaded on your SIM. There's no card, no bank login and no app to set up.

A provider sits in the middle to make that work. The casino doesn't talk to EE or O2 directly, so it hands the transaction to a billing company like Fonix or Boku, and that company settles with your network. You confirm the whole thing with a one-time SMS code sent to your handset. Key it back in, the charge is authorised, and the funds land in your casino balance in seconds.

That middle layer is the part most players never see, and it's exactly the part this page is about. The provider decides the fee, the limits and which networks clear your deposit. So knowing which one your casino uses tells you more than any toplist will.

Fonix vs Boku vs Payforit vs Zimpler in 2026

Four names get thrown around, but they don't carry equal weight any more. Fonix is the dominant rail on the white-label networks that power most UK pay-by-mobile casinos, including the Jumpman Gaming sites that make up the bulk of our list. It typically charges a flat £2.50 fee per deposit. Boku is the bigger, more mainstream provider, and you'll meet it more often at larger high-street-style brands than at the small white-label sites.

Payforit is the odd one out. It was never a single billing company, more an industry scheme that branded carrier billing across UK networks, and it's effectively retired now, absorbed back into plain carrier billing run by providers like Fonix and Boku. If a guide still pushes Payforit casinos in 2026, it's working from old copy.

Zimpler is the fourth, and it's drifted away from carrier billing entirely. These days Zimpler is far more of a pay-by-bank provider, moving money straight from your bank account rather than charging your phone bill. So treating it as a pay-by-mobile option, the way older lists do, gets you the wrong product.

What pay by mobile costs you

The fee is the part that catches people out. Most UK pay-by-mobile casinos run on Fonix and add a flat £2.50 charge to every deposit. That sounds small until you do the maths against a small stake. On a £10 deposit, £2.50 is a 25% surcharge. On £20 it's 12.5%, and on £30 it's 8.3%. So the bigger the deposit, the lighter the fee bites.

The flat shape of it means frequent small top-ups are the most expensive way to play. Three separate £10 deposits cost you £7.50 in fees for £30 of balance. One £30 deposit costs a single £2.50. Most sites set the minimum at £10, though some go as low as £5.

Not every brand charges it. The three independents on our list run differently: Oreels, Ivy Casino and Bet442 take no deposit fee at all, though they ask for a higher £20 minimum and stricter wagering in return. We set out exactly who charges what in our comparison so you can weigh the fee against the offer.

• £10 deposit + £2.50 fee = 25% surcharge
• £20 deposit + £2.50 fee = 12.5% surcharge
• £30 deposit + £2.50 fee = 8.3% surcharge
• Independents (Oreels, Ivy, Bet442): no fee, £20 minimum

The £30 daily cap, and why it isn't the casino's rule

There's an effective limit of around £30 a day on pay-by-mobile deposits, and it trips up a lot of players who assume the casino set it. It didn't. The cap comes from the phone-paid-services rules that govern charge-to-bill in the UK, so it sits on the rail itself rather than on any one operator. Per-transaction limits usually land somewhere between £10 and £30.

That means a second casino doesn't hand you a second £30. The ceiling applies across your carrier billing as a whole, so once you've hit it for the day, the rail simply declines further deposits until it resets. Some players treat that as a feature rather than a frustration, since it puts a hard, built-in ceiling on how fast money can go in.

It's worth saying plainly: this is a budgeting control, not a way to play more. If you want to set a tighter limit than the rail's, every UKGC-licensed casino lets you add your own deposit limit, and we'd encourage it. None of this makes gambling risk-free, and it isn't a way to make money.

You can't withdraw to your phone bill

Pay by mobile is a one-way rail. A network can charge you, because you owe the money on your next bill, but it can't pay you, because that would turn the rail into something a billing provider isn't set up to run. So you cannot withdraw winnings to your phone bill, full stop, at any UK casino.

Withdrawals route out by a different door instead: a debit card, a bank transfer, or an e-wallet. The practical takeaway is to add and verify one of those before your first cashout, because most operators want the receiving method confirmed in your own name before they release funds. Set it up early and you won't be scrambling when you actually win.

This is also where verification lands. Paying by phone hands the casino nothing but your mobile number and an SMS code, not your bank details, which is the genuine appeal. But "no bank details" doesn't mean "no ID". UKGC affordability and KYC checks still apply, and they usually kick in at withdrawal. We explain the full flow in our deposits guide.

How to tell which rail a site uses

You can usually work out the provider without guessing. Open the cashier and look at the deposit screen: the rail is often named outright as Fonix, Boku, or simply "Pay by Mobile". On the white-label Jumpman sites that dominate our list, with their £2.50 fee, £10 minimum and 10x wagering, the rail underneath is almost always Fonix.

The terms and conditions are the other tell. A flat £2.50 per-deposit charge is the Fonix fingerprint across the Jumpman estate. The three independents, Oreels, Ivy and Bet442, break that pattern with no fee, a £20 minimum and different bonus terms, which is a quick way to spot you're off the white-label network.

When in doubt, the operator's own banking or payments page is the source of truth, not a third-party list. Affiliate toplists routinely name rails the cashier no longer offers. We verify the method on each operator's page directly, which is why our list looks different from the copy-paste competition. Start from our homepage roster of the best pay by mobile casinos for the per-brand detail.

Apple Pay and Google Pay are not pay by mobile

This one trips up almost everyone, so let's be clear. Apple Pay and Google Pay are not pay by mobile. They live on your phone, which is where the confusion comes from, but they don't charge your phone bill. They charge a debit card you've linked to the wallet, which means the money comes off your bank account exactly as a normal card payment would.

That distinction matters because it changes everything that follows. A wallet payment carries no £30 carrier cap, usually no £2.50 fee, and it can support withdrawals, because there's a card behind it. Pay by mobile has the cap, often the fee, and no withdrawal route, because there's a phone bill behind it.

So if convenience on your handset is what you're after, a wallet is a fine choice. Just don't expect the privacy or the built-in ceiling of true carrier billing, because your card and bank details are in the chain either way.

Which UK networks work

Carrier billing works across the four main UK networks: EE, O2, Vodafone and Three. Most of the popular MVNOs that piggyback on them clear deposits too, including giffgaff, Tesco Mobile, Sky Mobile and Virgin Media O2, though support depends on the host network's billing agreement rather than the casino.

One catch worth knowing: some tariffs block gambling charge-to-bill outright, and a handful of prepaid SIMs never enable it at all. So if a deposit bounces, the casino usually isn't at fault. Check whether your specific tariff allows gambling payments before assuming the site is broken.

If a deposit fails on a virtual network, the fix is almost always at the carrier level, not the cashier. And whatever rail you use, keep the basics in view: this is 18+ only, and if gambling stops being fun, support is free and confidential through GambleAware on 0808 8020 133 or through the self-exclusion scheme GAMSTOP.