How Pay by Mobile Casinos Work

Q: What does “header enrichment” mean in Pay by Mobile flows?

It’s a mobile-network feature that automatically attaches your phone number (MSISDN) to the HTTPS request when you browse over 4G/5G, allowing the PSP to pre-fill your number without manual entry.

Q: How long is the SMS one-time password valid?

Typically 3–5 minutes; if you don’t confirm within that window, the session times out and no charge is applied.

Q: Why is there a £40 daily cap on carrier-billed gambling deposits?

It’s a joint requirement from the Phone-paid Services Authority and the UK Gambling Commission to limit risk and keep transactions within PSD2’s “micro-payment” exemption.

Q: Can I exceed £240 per month by making many small deposits?

No. PSD2 sets ~£240 as the combined monthly ceiling for carrier-billed digital purchases; the PSP and mobile network automatically block any transaction that would push you past that limit.

Q: Who carries the risk if I fail to pay my phone bill after depositing?

The mobile operator absorbs the short-term credit risk and can bar services or pursue collection if the bill remains unpaid.

Q: Does Pay by Mobile violate the UK credit-card gambling ban?

No. The UKGC classifies carrier billing as exempt because it’s telecom billing for low amounts with built-in spending caps, not a traditional credit facility.

Q: Can I withdraw casino winnings back to my phone bill?

Withdrawals aren’t supported via Pay by Mobile; you must cash out to a bank account, e-wallet, or another approved payout method.

Q: How does monthly settlement affect a casino’s cash flow?

The casino receives an immediate payment guarantee once the OTP is confirmed, but the actual funds arrive only after the carrier-to-PSP settlement cycle—often up to a month later—so cash flow is delayed and per-transaction fees are higher than card payments.

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Last Updated: 10 June 2025

UK players are able to deposit funds using their mobile phone number, charging the amount to a monthly bill or deducting it from pay-as-you-go credit. These deposits rely on direct carrier billing (DCB) systems, multiple authentication layers, and strict U.K. compliance.

This page explains—step by step—the exact technology, payment routing and regulatory logic that make Pay by Mobile casino payments possible.

How pay by mobile casinos work: Step by Step

Instead of entering card details, the player:

Selects “Pay by Mobile” on the casino’s cashier.
Enters a UK mobile number (or the site auto-detects it via header enrichment).
Confirms the charge with an SMS PIN or carrier-hosted prompt.
The casino credits the balance instantly; the amount appears on the next phone bill or is removed from PAYG credit.

No bank details, no e-wallet log-ins—just the phone. This method is possible because carrier billing providers (Boku, Fonix, others) act as an intermediary between the casino and the mobile networks.

How pay by mobile casinos work: Technical Flow

User initiates: Chooses Pay by Mobile & enters amount.
Casino API call: Backend sends Charge to the PSP (aggregator).
PSP routing: The aggregator routes the request to the correct mobile network operator (MNO).
User authentication: SMS OTP (or carrier confirm page). User enters PIN / taps “Yes”.
MNO authorisation: Carrier checks balance / limits and approves or denies in real time.
PSP callback: Aggregator notifies casino; casino instantly credits player.
Settlement: Carrier settles with PSP; PSP settles with casino (usually on a monthly schedule).

What is SIM verification and two-factor authentication?

Header Enrichment: Auto-detects MSISDN when the device is on 4G/5G (no Wi-Fi).
SMS OTP: 4- or 6-digit PIN sent via SMS; user enters it to complete the charge.
Carrier Confirm Page: A secure landing page hosted by the MNO; user taps “Confirm”.
Tokenisation: PSP stores an alias of the phone number so future deposits can bypass data re-entry while preserving privacy.

Explaining the PSP gateway architecture

The casino integrates a single PSP API.

Unified endpoint converts the request into carrier-specific formats.
Routing logic decides which MNO gateway to call (EE, O2, Vodafone, Three).
Fail-over, retry and SMS delivery monitoring are handled in the PSP layer.
Alias store keeps customer tokens for repeat billing and fraud checks.

Real-time pay by mobile casinos authorisation

Stage	When?	Action
Authorisation	~1–3 seconds	MNO approves; casino credits funds immediately.
Billing	Instant (PAYG) or next bill cycle (post-paid)	User pays via mobile bill or airtime.
Settlement	Typically monthly	MNO → PSP → casino, net of fees.

What is the UK compliance matrix?

Phone-paid Services Authority: Double opt-in, transparent pricing, receipt SMS.
UK Gambling Commission: Age verification, AML, £40/day carrier billing cap.
PSD2 Exemption: Digital services under ~£240/month via telecom billing.
Credit Card Ban: Carrier billing exempt (small values, telco-mediated).

Three regulators oversee phone-bill deposit rules and regulations: Ofcom, the PSA legacy code, and the UK Gambling Commission (UKGC).

4 Key UK Providers

Boku: Global PSP; offers single API covering all UK carriers; instant SMS-PIN flow.
Fonix: UK-focused DCB specialist; deep carrier ties; identity & compliance add-ons.
Payforit (Legacy): Historic UK scheme; its flow standards underpin modern “Charge to Mobile”.
Apple Pay (Comparison): Tokenised card payment—not carrier billing—but often offered alongside.

Common failures and errors with pay by phone bill deposits

For an in-depth run through of common errors and fixes, you can read our full Troubleshooting Guide.

Insufficient PAYG credit → automatic decline.
User hits daily £40 carrier limit → decline.
Wrong OTP or expired session → fail; no charge taken.
Premium bar on number → request blocked; user must lift bar with carrier.
Delayed SMS → fallback to “resend code” or voice call if supported.
Post-paid non-payment → carrier may claw back; low incidence due to limits.

Summary table of how pay by phone bill casino deposits work

Aspect	Key Points – UK Pay-by-Mobile Casino Payments
What it is	Charge-to-mobile deposits: amount added to monthly phone bill (contract) or deducted from PAYG credit.
Player flow	Select “Pay by Mobile” in cashier. Enter / auto-detect UK number. Confirm via SMS PIN or carrier prompt. Casino credits instantly; charge appears on bill/PAYG balance.
Back-end flow	Casino → PSP API → MNO. MNO authorises in 1-3 s (balance & cap check). PSP notifies casino; player sees funds. Monthly settlement: MNO → PSP → casino (minus fees).
Authentication	Header enrichment (auto MSISDN on 4G/5G). SMS OTP (4–6-digit code). Carrier host page “Confirm”. Tokenisation for repeat deposits.
Key providers	Boku (global), Fonix (UK-centric), legacy Payforit rails; Apple Pay listed for comparison (tokenised card, not DCB).
Compliance layers	PSA: double opt-in, clear pricing SMS. UKGC: age-/AML-checks, £40/day cap. PSD2 exemption: telecom digital payments ≤ £240 / month. Credit-card ban does not apply to carrier billing.
Typical limits	£30 per transaction, £240 per 24 h, £300 per 30-day rolling window; casinos may impose tighter caps.
Common errors	Insufficient PAYG credit. Daily cap hit (£40). Wrong/expired OTP. Premium bar on number. Delayed SMS – use “resend”.

Pay by Mobile Casino Payments (UK) FAQs

What does “header enrichment” mean in Pay by Mobile flows?

How long is the SMS one-time password valid?

Why is there a £40 daily cap on carrier-billed gambling deposits?

Can I exceed £240 per month by making many small deposits?

Who carries the risk if I fail to pay my phone bill after depositing?

Does Pay by Mobile violate the UK credit-card gambling ban?

Can I withdraw casino winnings back to my phone bill?

How does monthly settlement affect a casino’s cash flow?

Chris Vaughan Senior Writer & Editor

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Chris Vaughan is a Senior Writer and Editor at GamblingAuthority. He has more than 18 years of experience in the iGaming industry and has great knowledge of game developers, trending games and casino research.