Craft is knowing how many family-name fields you need and which law owns the next change.
Do not buy a crest as a research method.
Steps
- 1Count the surnames
One hereditary, two Spanish-style, or a patronymic.
Write them in local order first.
- 2Fix romanisation
Pick a passport spelling and reuse it.
김 can be Kim or Gim — consistency beats purity wars.
- 3Map marriage options
Change, keep, hyphenate, dual.
Namensrecht and koseki are not blog advice.
- 4Train the form
Passport, bank, school: same string.
Hyphens and spaces are frequent break points.
- 5Explain to foreigners
A one-line note: “two surnames, neither is a middle name.”
Saves years of correction.
- 6Plan children’s tags
Order and which lineages drop.
This is law plus values, not luck.
Checklist
- Local order written — Family name first if that is home.
- Second surname preserved — Spanish/Portuguese systems.
- Patronymic not treated as clan — Iceland.
- Koseki/marriage rule checked — Japan and similar.
- Romanisation locked — One Latin form per passport.
- No crest-as-proof — Heraldry ≠ genealogy.
- Airline fields tested — Given vs surname swap errors.
- Children’s future string drafted — Before the registrar asks.
Pitfalls
- Middle-name-ing a second surname — A classic English-form injury to Spanish names.
- Assuming Kim is one clan — Korean homophones hide many lineages (bon-gwan).
- DIY hyphen piles — Unusable in software and in shouting across a pitch.
- Surname personality quizzes — Occupational etymology is history, not a career plan.
Tools
- Passport/ICAO guide — How family names are machine-printed.
- Civil-code summaries — Namensrecht, Spanish civil code, koseki guidance.
- INE / KOSTAT / census surname tables — Frequency as demography, dated.
- Style guides for journalists — When to use both Spanish surnames on second mention.
If the form has one last-name box, you are already doing policy. Fill it on purpose.