Sri Lanka Patent Registration & Maintenance Fee Calculator

The calculator applies the Schedule of Fees published by the National Intellectual Property Office of Sri Lanka (NIPO) under the Intellectual Property Act No. 36 of 2003 and the Fees Regulations gazetted as Extraordinary Gazette No. 2146/37 of 27 October 2019. A patent's cost has two distinct parts — a one-off cost to obtain grant, and a stream of annual maintenance fees that rise as the patent ages — and the tool keeps them separate so the lifetime cost is honest.

1. Upfront cost — obtaining grant

For a full application (file → grant), three one-off lines apply:

1. Application for grant. Rs 5,650 — lodged with the specification, claims and drawings.
2. Request for substantive examination. Rs 7,350 — NIPO examines the invention for novelty and inventive step.
3. Grant of patent & certificate. Rs 5,650 — paid once the patent is granted and the certificate issues.

A Convention or PCT priority claim adds Rs 2,825per claim. If you choose "File only", the examination and grant lines are dropped — you pay them later. The upfront total is:

upfront = application + examination + grant
+ (priority × claims)

2. Annual maintenance fees (annuities)

Under Section 86 an annual fee is payable in advance to keep the application or patent alive. The first annuity falls due before the start of the second year counted from the filing date, and annuities continue each year up to the 20-year term set by Section 83. The schedule is stepped — the per-year fee rises in bands as the patent ages:

• Years 2–5: Rs 2,825 per year
• Years 6–10: Rs 5,650 per year
• Years 11–15: Rs 8,475 per year
• Years 16–20: Rs 11,300 per year

For "Years to maintain = N", the calculator counts an annuity for every year from 2 through N inclusive — that is N − 1 payments, since year 1 is covered by the filing fee. Each year is priced from the band it falls in, so the band boundaries (year 5 → 6, year 10 → 11, year 15 → 16) are handled exactly with no off-by-one error:

annuities(N) = Σ for year y = 2 … N of annualFee(y)

3. Late annuity, restoration and other recordings

Section 86(2) allows an annuity to be paid within a 6-month grace period on payment of the fee plus a surcharge of Rs 2,825; the late-annuity toggle adds that surcharge. If a patent has already lapsed, restoring it costs Rs 11,300 plus the outstanding annuity. Assignment / transmission (Rs 5,650), change of name or address (Rs 2,825) and licence recording (Rs 5,650) are flat per-act fees from the schedule.

Verification and rounding

The calculator runs two independent derivations of the grand total — a line-item walk and a flattened algebraic formula that sums the annuity year-by-year — and shows the "verified" badge only when both produce the same integer rupee figure. NIPO publishes all fees as integer LKR amounts and the tool never introduces fractional rupees. Years to maintain is constrained to 1–20: anything above the 20-year term is capped with a warning, and a value below 1 or a non-number returns a clear validation message rather than a silent zero. This calculator covers the Sri Lankan national fees only — WIPO and PCT international-phase fees are a different regime and are out of scope; a Convention/PCT priority claim line is included, but not the international filing fees themselves. For the brand side of an invention, the trademark registration fee calculator covers the separate NIPO trademark schedule.

Three scenarios that map to the most common Sri Lankan filing patterns, including the band-boundary edge case. Plug each into the calculator above — the itemised breakdown should match the lines below to the rupee.

The contrast between Example 1 (about Rs 30k for 5 years) and Example 2 (about Rs 160k to term) is the core insight: the recurring annual fees, not the headline application fee, dominate a patent's lifetime cost.

• National Intellectual Property Office of Sri Lanka — official site & Schedule of Fees (Patents)
• Intellectual Property Act No. 36 of 2003, Part II (Patents) — ss.83 (term), 86 (annual fees, grace, lapse)
• WIPO Lex — Sri Lanka Intellectual Property Act No. 36 of 2003 (full text)

NIPO patent fees were last cross-checked against the official Schedule of Fees on 2026-06-27. The schedule is gazetted under the Intellectual Property Act No. 36 of 2003 (Fees Regulations, Gazette Extraordinary No. 2146/37) and may be amended without notice — always confirm the current fee at nipo.gov.lk before filing or paying an annuity.