Identifier: C2T7L3 | Revision: 2026-10-26

Decision and objectives

An investment's after-tax result needs the investor's legal status and the rule applicable to each payment. Withholding is tax deducted at source; declaration is reporting income on a return. A withholding amount of zero does not by itself mean no declaration or final tax. An annual guide is evidence for its stated period, not a timeless rate table.

Objectives: Identify the required tax facts; Apply a supplied withholding/declaration schedule; Reconcile withheld tax and later cash liability.

Prerequisites: C2T7L2.

Mechanics

Before calculating, record residence and taxpayer status; individual or business holding; issuer and instrument type; issue and acquisition dates; coupon, sale and redemption dates; income year; currency conversions; applicable rule effective date; and any aggregation, threshold, exemption or credit rules. The actual GIB February 2026 guide distinguishes Eurobond income from the temporary Article 67 framework and gives residence-specific examples. It is based on law at publication and primarily discusses 2025 income declarations. This lesson does not assert an actual 2026 withholding rate or annual threshold.

Temporary acquisition-dependent changes can make two otherwise similar holdings taxable differently. A net comparison must preserve that distinction instead of selecting whichever rate is advertised. Where current amendments cannot be verified, supply missing-data questions or omit an actual-rate conclusion.

Price and return drivers

Teaching calculation: net income cash at receipt = gross income − tax withheld. Later additional tax = liability under the supplied schedule − creditable withholding, floored at zero when no refund is modelled. Net total gain = gross economic gain − all investor costs − total tax; do not subtract the same withholding again after computing the final total liability. Gross sale proceeds are not automatically the taxable gain.

Worked case

Explicitly fictional tax jurisdiction and schedule, not Turkish law: income year 2026; resident individual investing outside a business; domestic bond issued 15 January 2026, acquired 1 February 2026, sold 30 September 2026; fictional schedule effective 1 January 2026. Gross coupon TRY 20,000; coupon withholding 10%, creditable; taxable sale gain TRY 6,000; declaration required because total relevant income 26,000 exceeds fictional threshold 25,000. Once crossed, all 26,000 is taxable at fictional flat 15%; no other income, allowances or offsets. Economic gain before tax and costs equals 26,000; investor costs TRY 500 are not deductible under this supplied schedule.

Withholding = 20,000×0.10 = TRY 2,000; coupon cash credited TRY 18,000. Declared base = 20,000+6,000 = TRY 26,000. Total tax = 26,000×0.15 = TRY 3,900. Additional payment = 3,900−2,000 = TRY 1,900. Net economic gain = 26,000−3,900−500 = TRY 21,600. Reserve the 1,900 even though the broker has already withheld tax.

Adverse case

Change only sale gain to TRY 4,000. Total relevant income 24,000 is below the fictional threshold; the supplied rule now says no declaration and coupon withholding is final, with sale gain untaxed. Total tax TRY 2,000; net gain = 24,000−2,000−500 = TRY 21,500. Crossing the threshold changes the whole taxable base under this fictional rule, not only the excess. Actual Turkish thresholds and aggregation must be checked independently; this example must never be used to file a return.

Practical use

For production, retrieve GIB guidance for the income year, binding law and later amendments, and instrument acquisition-date rules. Document residence and whether business income rules apply; nonresident treatment cannot be copied from a resident example. Preserve actual FX conversion evidence and fees. For direct Eurobonds versus a domestic fund, verify each wrapper separately rather than transfer a fund withholding rule to the bond. Defer any real filing conclusion if decisive dates or amendments are missing.

Decision boundaries

An after-tax comparison is suitable only when its rule scope and cash timing are explicit. Never call gross return net because a dealer withheld nothing, or treat purchased accrued cash as automatically deductible without the legal method. Decline a proposed trade whose required after-tax spending amount cannot be established from available records. Seek qualified tax advice for an actual return; the educational task is to identify and reproduce the calculation boundary.

Practice and references

Exercise: use a different fictional schedule: income year 2026, resident nonbusiness individual, bond issued/acquired 1 March 2026, fictional rule effective 1 January 2026. Coupon TRY 12,000, taxable sale gain 3,000; all relevant income declared at flat 20% with 10% coupon withholding credit; investor costs 200 nondeductible; no threshold. Answer: withheld 1,200; total liability (12,000+3,000)×20% = 3,000; later payment 1,800; net economic gain 15,000−3,000−200 = TRY 11,800.

Takeaway: date the rule and the investor facts, then separate receipt cash from final tax liability.

Reference guide: debt-portfolio, net-debt-tax-cash, Withholding, Declaration, Tax residency.

Next: C2T7L4. Topic test: C2T7.

Primary sources (checked 2026-10-26; changing terms require a publication recheck): GIB investment income tax guide, February 2026 — Eurobond income; temporary Article 67; resident and nonresident examples.

Shared reference guide