1. What PIN verification is and why it exists. Google will not pay out advertising earnings until it has confirmed that the payee and the payments address on the account are real. Address verification is the step that proves the address: once your earnings hit the verification threshold, Google mails a unique 6-digit Personal Identification Number (PIN) to your payments address and you enter it back into the account. AdMob's overview (https://support.google.com/admob/answer/2772302) states it directly: "To protect the security of your account, Google requires you to verify your address before we can send you any payments." AdSense carries the identical rule (https://support.google.com/adsense/answer/157667). The PIN is sent by international standard mail and there is no tracking number, so the address must be one that your local postal service actually delivers letters to.
2. Your PIN is not your publisher ID. This trips people up constantly. The PIN is a unique 6-digit number Google generates when the account reaches the verification threshold; the publisher ID is a permanent account identifier of the form pub-1234567890123456. Quote: "Your PIN is a unique 6-digit number that Google generates when your account reaches the verification threshold. Your PIN is not the same as your publisher ID." (https://support.google.com/admob/answer/3198657). If you see a pub-... string, that is not something to type into the PIN box.
3. When the PIN is triggered - the verification threshold. Google maintains two separate thresholds. The verification threshold is the earnings level at which you must verify identity and address; the payment threshold is the minimum balance required before Google will actually issue a payment. For a USD account the threshold table (https://support.google.com/admob/answer/2772208) reads: Verification (identity / address) = $0 / $10; Payment method selection = $10; Payment = $100; Cancellation = $10. So for USD the PIN is generated around $10 of confirmed earnings, while the actual payout does not go out until $100. The doc is explicit that the amount "can vary depending on your location" and that thresholds follow the account's reporting currency - do not assume $10 if your account is in another currency. The table lists local equivalents (e.g. EUR 10, GBP 10, JPY 1000, AUD 15, IDR 130,000) for the address / payment-method thresholds.
4. Identity verification comes first. Since 2023 Google split verification into identity and address. The PIN will not be mailed until identity verification is complete. AdMob: "If we've asked you to verify your identity, we won't send your PIN until after you've successfully completed identity verification." So if your PIN never arrives and your balance is above the threshold, first check Payments > Verification for an outstanding ID request. AdSense adds a useful nuance: "Depending on your location, you may not need to complete address verification if you've already passed online identity verification. Click Payments, then Verification check to find out if you're required to complete address verification." In other words, always read the Verification check page before assuming a PIN is needed.
5. Timeline and the hard deadline. Delivery: "It usually takes 3 weeks for your PIN mailer to arrive." (AdMob / AdSense). Replacement PINs can only be requested once every 3 weeks, so the practical cycle is a 3-week wait per request. Deadline: "You'll have 4 months from the date your PIN is generated to complete address verification. If you haven't verified your payments address after 4 months, we'll stop showing ads on your pages." The 4-month clock starts on PIN generation, not on the day you notice the notice. Missing it stops ad serving on your apps and pages - a revenue-stopping event that is far worse than the verification itself.
6. Entering the PIN - and the three-strikes rule. When the mailer arrives, enter the PIN in the account immediately. AdSense spells out the penalty: "If you enter your PIN incorrectly 3 times, your account will stop showing ads." AdMob phrases it as: "If you enter your PIN incorrectly 3 times, you will fail the address verification and your account will stop showing ads. To reset your PIN verification limit, request a replacement PIN." So treat the three attempts as real; if the first entry is rejected, stop and re-check the digits and the account rather than burning attempts.
7. If the PIN never arrives - replacement PINs. You request a replacement from Payments > Verification (AdMob) or Payments > Verification check (AdSense), then Resend PIN. Key facts: replacement PINs are exact duplicates of the original, not new numbers - "Your replacement PIN will be an exact duplicate of the original PIN. You can enter any of the PINs you receive, regardless of which one arrives first." You can only request one new PIN every 3 weeks ("You can only request a new PIN every 3 weeks."). And the escalation path: "If you've requested the 4th replacement PIN and you still haven't received it after 3 weeks, go to our AdMob PIN troubleshooter" (AdSense: PIN troubleshooter). So after four attempts you are routed to a troubleshooter / support flow rather than being stuck in a loop.
8. What a valid payments address looks like. Google defines a valid payments address simply as one that can receive standard mail, and gives a format to follow: Address line 1 = house or block number, street name, neighbourhood / district name, city name; Address line 2 (if applicable) = unit number, floor number, building name; postal code = postcode / ZIP. In practice this means no PO-box-only lines where the carrier will not deliver, no vague "near X" descriptors, and a recipient name that matches the payee. A fuzzy or undeliverable address is one of the documented reasons a PIN is not received, and the fix is to change the address to one that can receive standard mail.
9. Address changed after the PIN was mailed. A frequent cause of "the PIN is going to an address I no longer use": if you edited your payments address after the PIN was generated, the mailer went to the old address. The guidance (https://support.google.com/admob/answer/3198657) is to wait 3 weeks from the original send date and then request a replacement PIN to the current address: "The PIN was likely sent to your old payments address. You can request a replacement PIN 3 weeks after the original send date to ensure it arrives at your current payments address."
10. Fraudulent-address flag. If an address has been associated with fraudulent activity, Google will not simply accept an in-place correction; you must change to a new, different, valid postal address and then request a PIN: "Your new address must be different from your previous one." If no valid payments address can be supplied, ads stop showing on your app. This is an enforcement-adjacent state; treat it as the documented procedure, not something to be argued around.
11. Missed the 4-month window - how to recover. If verification lapsed and ads have stopped, the documented path is to contact Google to extend the address verification timeline ("To extend your address verification timeline, please contact us."). Recovery is possible but requires a support contact, so preventing the lapse (calendar the 4-month deadline from PIN generation) is the cheaper option.
12. Practical checklist for a monetizing developer. (1) Before you rely on payouts, open Payments > Verification and read whether identity and / or address verification is outstanding. (2) Fill the payments address in a precise, mail-deliverable format with a payee name that matches your ID and bank; fuzzy addresses are the top cause of undelivered PINs. (3) Finish identity verification first, otherwise the PIN is never mailed. (4) Note the PIN generation date and set a 3-week reminder; if nothing has arrived by then, request a replacement (one request per 3 weeks). (5) When the mailer arrives, enter the PIN carefully - three wrong entries stop ad serving. (6) Set a hard reminder at 4 months from PIN generation: that is when ad serving stops for unverified addresses. (7) If the address was flagged as fraudulent, change to a genuinely different valid address before requesting a PIN. (8) Remember the verification threshold (about $10 USD) and the payment threshold ($100 USD) are different gates - clearing the PIN does not by itself trigger a payout; the balance must also cross the payment threshold.