Got it—here’s a practical, Philippines-specific explainer on visa overstay exceeding 16 months. I’m not searching the web, so this is general legal/administrative knowledge you can use as a starting point; always confirm current rates and forms with the Bureau of Immigration (BI). This is not legal advice.

1) What “overstay” means in PH law

Legal basis: The Philippine Immigration Act of 1940 (Commonwealth Act No. 613) and BI’s implementing rules.
Overstay occurs when a foreign national remains in the country beyond the last authorized stay date printed/stamped in the passport (including any BI-approved extensions).
It’s an administrative immigration violation that can trigger fines, fees, and—if prolonged or aggravated—deportation and blacklisting.

2) Why “16+ months” matters

Once you’re >12 months out of status, BI treats the case as prolonged overstay. You’ll almost always need to resolve it at a BI office (not at the airport) before departure.
At >16 months, you’re well past ordinary late-extension scenarios. Expect higher cumulative charges, possible investigation/hearing, and stricter scrutiny before BI lets you extend retroactively or depart.

3) Penalties & fee buckets you should expect

Exact pesos change over time, but the structure is stable. BI typically computes an overstay case by stacking these buckets:

Base overstay fine/surcharge
- A per-month penalty (sometimes computed in blocks) for every month (or fraction) you were out of status.
- Multiplies quickly at 16+ months.
Unpaid visa extension fees (catch-up extension)
- BI usually requires you to “cure” the gap by paying the missed 9(a) tourist extensions (or the relevant temporary stay extensions) as if you had extended on time, plus any late penalties per extension cycle.
- If your nationality originally entered visa-free (the 30-day waiver), BI will reconstruct the extension ladder you should have taken.
ACR I-Card fees (if applicable)
- For long stays, BI often requires/renews an ACR I-Card (Alien Certificate of Registration) for temporary visitors who exceed a threshold stay (commonly >59 days). If you never got/renewed it, BI may collect it retroactively with penalties.
ECC (Emigration Clearance Certificate)
- Mandatory if you stayed ≥6 months (tourists: ECC-A).
- Overstays >6 months almost always need to secure ECC before departure (valid briefly; time it with your flight).
Motion/Order fees & hearing costs (if escalated)
- Prolonged overstays may be routed to Legal Division for a charge sheet and order to pay.
- You may see fees tied to motions for reconsideration, lifting/recall of a charge, or waivers.
Visa downgrading (for non-tourist categories)
- If you once held work/student/missionary/spousal status that lapsed, BI can require a downgrade to tourist before settlement and exit, with downgrading fees.
Express lane / certification / documentary fees
- BI commonly adds express processing and certification line-items. Not optional at some counters.

Bottom line: At 16+ months, expect a five-figure to six-figure PHP total in many cases once all missed extensions, ACR, ECC, surcharges, and admin items are added. The exact tally depends on your nationality, original status, gaps, and BI’s current schedule of fees.

4) Administrative outcomes: What can happen

Regularization & departure allowed: Most tourist overstays—even long ones—are resolved by paying everything and departing (often with no re-entry bar).
Order to Leave (OTL): BI may issue an OTL with a short timeframe to exit after payment.
Deportation & Blacklist: If there are aggravating factors (e.g., ignoring BI orders, working without authority, criminal issues, fraud), BI can deport and blacklist you (bar to re-entry until lifted).
Custody/detention: Rare for “clean” administrative overstays, but possible if there’s an active warrant, watchlist/hold-departure, or ongoing deportation case.

5) Maximum stay rules (why they matter to your case)

The Philippines caps cumulative tourist stays (varies by category). Historically:
- Visa-waiver nationals could extend repeatedly up to a long maximum (often 36 months);
- Visa-required entrants typically had a shorter cap (often ~24 months).
If your overstay exceeds the cap, BI can still let you settle and depart, but fresh extensions (to remain longer) may be refused; you may be required to leave after payment.

6) Can you fix it at the airport?

Usually no for >6 months overstay, and especially not for 16+ months. Airline counters will send you to BI main or a district office first.
The airport BI desks typically won’t compute long overstays (they’ll check your ECC and receipts and then clear you if everything’s already settled).

7) Practical step-by-step to rectify a 16+ month overstay

Do not wait until flight day. Go to a BI office (Intramuros Main Office is safest for complex cases) weeks before your intended departure.
Bring: Passport (with all pages), photocopies, 2×2 photo (helpful), proof of funds, and onward ticket proposal.
Counter routing: You’ll be sent through Assessment/Overstay → Cashier → possibly Legal → ACR desk → ECC counter.
Computation issuance: BI will compute all arrears (missed extensions + per-month penalties + ACR + ECC + admin).
Pay and keep originals of all Official Receipts.
ECC issuance: After payment and any required checks, secure your ECC-A (tourists) or relevant ECC category.
If given an OTL, book your flight within the OTL validity and leave.
Airport day: Arrive early, present passport + ECC + all BI receipts. Expect extra questions at immigration.

8) Special situations

Worked without a work visa/AEP: BI may add separate violations; the case can escalate to deportation/blacklist.
Overstay + expired passport: You’ll be told to renew at your embassy first; BI won’t extend beyond a passport’s validity.
Married to a Filipino / pending 13(a): You might request conversion to a resident visa instead of departure, but with a 16+ month overstay, BI may still require you to settle arrears and follow their visa conversion workflow.
Minors: Penalties are usually assessed on the responsible parent/guardian.
Medical or humanitarian grounds: You can submit supporting documents (hospital records, etc.) and a motion requesting leniency on fines or process—not guaranteed, but sometimes considered.

9) Blacklisting & lifting (if it happens)

Blacklist can follow a deportation order or serious/aggravated overstay.
Lifting generally needs a formal request, supporting affidavit, clearance of all arrears, and payment of lifting/legal fees; decision is discretionary.

10) Timelines & logistics

Computation + payment can be same day for straightforward cases; longer if routed to Legal or if records must be reconstructed.
ECC has limited validity (often ~30 days); time your flight within its validity.
Keep multiple photocopies of everything; immigration may ask at different points.

11) How BI decides your final bill

Key variables BI will look at:

Your last authorized stay date and all stamps/receipts on record
Nationality and original entry class (visa-free vs. visa-required)
Whether you crossed maximum cumulative stay thresholds
Whether you worked/studied without proper visas
Any prior BI violations, watchlist hits, or derogatory records

12) Risk-reduction & good practices

Be candid and cooperative with officers.
Don’t over-argue computations; if something looks off, politely request a re-check with dates.
Use the main office for complex/long overstays.
If your situation is tangled (old work visa, pending cases), consider retaining a PH immigration lawyer or an accredited liaison.

13) Quick FAQ for 16+ month overstays

Will I go to jail? Highly unlikely for a clean administrative overstay. Detention is more about pending deportation or derogatory hits, not simple fee settlement.
Can I stay after paying? Often no—BI may require you to depart after curing the overstay, especially if you’re past max stay caps.
Will I be banned? Not usually for simple tourist overstays once paid and you exit; aggravated cases can be blacklisted.
Can I fly without an ECC? If you stayed ≥6 months, no—you’ll be off-loaded and told to get an ECC first.
Can I fix this online? Overstays this long almost always require in-person processing.

If you want, tell me:

your nationality,
entry date/last authorized date (from your passport), and
whether you ever extended or got an ACR I-Card— and I’ll walk you through a tailored computation game plan (without looking anything up).