What Is a Fishmonger? What They Do and What to Ask

Jump to

Updated August 2026 · 8 min read · UK Japanese knife specialists

Fishmonger: the definition

Fishmonger (noun) — a person or business that sells raw fish and seafood, and prepares it for the customer.

The word is a compound of "fish" and "monger". Monger comes from the Old English mangere, meaning a trader or dealer, and it survives in a handful of other English words — ironmonger, costermonger, and the more figurative warmonger and scaremonger. It has nothing to do with fishing itself. A fisherman catches; a fishmonger buys, prepares and sells.

In the UK the term covers a broad range of businesses: an independent high-street shop, a stall at a market, the counter inside a supermarket, a mobile van round, and increasingly a next-day delivery service ordering direct from day boats. Any of them selling fish to the public has to be registered with its local authority as a food business, whatever the format.

What does a fishmonger actually do?

Most of the job happens before you get to the counter, and most of the skill is invisible.

Buying and judging quality

Fish is bought through wholesale markets, direct from boats, or via suppliers — the romantic image of the fishmonger meeting the boat at dawn is true for a handful of coastal businesses and not for most. What is universally true is the early start, because the fish has to be bought, moved, iced and laid out before the shop opens.

Judging quality is the core competence. A good fishmonger reads the eyes (clear and domed rather than sunken and cloudy), the gills (bright red rather than brown), the flesh (firm and springing back when pressed), and the smell — fresh fish smells of the sea and of very little else. That judgement is what you are paying for.

Preparing it

This is the part people underuse. A fishmonger will, as a matter of routine and usually at no extra charge:

• Gut and scale a whole fish
• Fillet it, and skin the fillets
• Pull the pin bones
• Portion fillets to a size you specify
• Butterfly a fish, or trim it for stuffing
• Shuck oysters, prepare crab, devein prawns
• Bag the bones and head separately for stock

Advising

And they will tell you what is good today rather than what you walked in intending to buy — which is usually the better dinner and often the cheaper one.

What to ask a fishmonger for

If you have ever stood at a counter and just pointed, this is the section worth having. None of these requests is unusual and none of them is cheeky.

Say this	And you get
"What's good today?"	The single most useful question. Freshest stock, often better value than the thing you came in for
"Can you fillet that and keep the bones?"	Ready-to-cook fillets plus a free stock base
"Skin on or off?" — answer on for pan-frying	Crisp skin, and the fillet holds together in the pan
"Two portions of about 150g each"	Even pieces that cook in the same time
"Can you pin-bone it?"	No tweezering at home; worth it on salmon and sea bass
"When was this landed?"	A straight answer from a good counter, and a useful tell if you don't get one
"What's a cheaper fish that would work here?"	Usually a better answer than the recipe gave you

Buying well: freshness and sustainability

Freshness. Whole fish is easier to judge than fillets, which is part of why it is often better value. Look for clear, domed eyes; bright red gills; firm flesh that springs back; a clean sea smell. Skin should look wet and bright rather than dull and dry. On fillets, look for translucent, tight-grained flesh with no gaping between the muscle blocks and no browning or dryness at the edges.

Sustainability. The UK reference point is the Marine Conservation Society's Good Fish Guide, which rates seafood on a traffic-light system — green for "best choice", amber for "OK but improvements needed", red for "fish to avoid". Ratings depend on three things: what the species is, where it was caught or farmed, and how. That is why the same species can be green from one fishery and red from another.

The guide covers more than 600 ratings across roughly 130 species and is updated twice a year with the latest scientific advice, so a rating you remember from a few years ago may well have changed. A good fishmonger will know where their fish came from and how it was caught — asking is reasonable, and the answer tells you a lot about the shop.

How do you become a fishmonger in the UK?

There is no single mandatory qualification, and you do not need a degree — the old claim that you need to study marine biology is simply wrong. It is a skilled trade learned mostly on the job. That said, there are formal routes:

• Apprenticeship. In England there is a Level 2 fishmonger apprenticeship; the standard was revised to cover wholesale as well as retail fishmongering from March 2025. Wales, Northern Ireland and Scotland have Level 2 and Level 3 fish and shellfish industry frameworks.
• Short courses. Industry body Seafish and the Seafood Training Academy run filleting and mongering courses for new entrants and existing staff.
• The Master Fishmonger Standard, developed by the Fishmongers' Company, is the recognised mark of craft-level skill in the trade.
• Food hygiene. A food hygiene qualification is strongly recommended, and the business itself must be registered with the local authority.

The practical requirements are unglamorous: very early starts, cold and wet hands, and knife skills that only come from repetition.

What knives does a fishmonger use?

Fish is soft, slippery and full of fine bones, so the tools are specialised. There is no single "fishmonger's knife" — there are three or four blades doing distinct jobs:

Knife	Shape	Job
Filleting knife	Long, narrow, flexible — typically around 17–21cm	Running along the backbone; skinning fillets
Deba	Short, thick, heavy, single-bevel	The Japanese fish-breaking knife — heads and collar bones
Yanagiba	Very long, thin, single-bevel	Slicing sashimi in one clean draw
Boning knife	Narrow, pointed, six inches or so	The realistic all-rounder — skinning, trimming, portioning

Two corrections to things you'll read elsewhere, including on an earlier version of this page. A nakiri or chukabocho cleaver is a vegetable knife — it is not a fish cleaver and should not be taken to fish bones. And a deba is not "a cleaver with a pointed tip"; it is a distinctly Japanese single-bevel knife with its own geometry, which we cover in what is a deba knife.

Being straight with you: we don't currently stock a deba, a yanagiba or a dedicated filleting knife. If you are setting up as a fishmonger, those are the specialist tools to go and find. What we can genuinely help with is the home cook's end of this, below.

What you actually need at home

Here is the honest position. If you have a good fishmonger, let them do the filleting — they are faster, better, and they'll do it for free. What you need at home is a knife for portioning, trimming and skinning, and one for everything that happens after the fish is on the board.

One thing worth knowing about fish and steel

Fish is wet and salty, and salt water is hard on a blade. VG10 is a stainless steel and resists corrosion well, but it is not rust-proof. Rinse and dry the knife as soon as you have finished — not at the end of the evening — and never leave it sitting damp. If you have already found spots, removing rust from a Japanese chef knife covers the fix, and how water damages a knife covers why it happens.

Frequently asked questions

What is a fishmonger?

A fishmonger is a person or business that buys, prepares and sells raw fish and shellfish. That includes independent shops, market stalls, supermarket fish counters, mobile van rounds and online delivery services. The skilled part of the job is judging freshness and preparing fish to order — gutting, scaling, filleting, pin-boning and portioning.

What does a fishmonger do?

They buy fish through wholesale markets, direct from boats or via suppliers, judge its quality, ice and display it, and prepare it for customers. Routine preparation includes gutting, scaling, filleting, skinning, pulling pin bones, portioning to a requested size, shucking oysters and preparing crab. They also advise customers on what is good that day and how to cook it.

Where does the word fishmonger come from?

It combines "fish" with "monger", from the Old English mangere, meaning a trader or dealer. The same ending survives in ironmonger and costermonger. It refers to selling rather than catching — a fisherman catches the fish, a fishmonger buys, prepares and sells it.

What is the difference between a fisherman and a fishmonger?

A fisherman catches fish at sea. A fishmonger buys the landed catch, prepares it and sells it to the public. A few coastal businesses do both, but they are separate trades with separate skills — one is seamanship and fishing, the other is quality judgement, knife work and retail.

Will a fishmonger fillet fish for you for free?

Yes, in almost all cases. Filleting, skinning, pin-boning and portioning to a size you specify are normal parts of the service and usually carried out at no extra charge. Ask them to bag the bones and head separately as well — they make excellent stock and are otherwise thrown away.

How can you tell if fish at the counter is fresh?

On a whole fish, look for clear domed eyes rather than sunken cloudy ones, bright red gills rather than brown, firm flesh that springs back when pressed, and bright wet-looking skin. It should smell of the sea and very little else. On fillets, look for translucent tight-grained flesh with no gaping between the muscle blocks and no browning or dryness at the edges.

How do you become a fishmonger in the UK?

There is no single mandatory qualification and no degree is required. In England there is a Level 2 fishmonger apprenticeship, with the standard revised to cover wholesale as well as retail from March 2025; Wales, Northern Ireland and Scotland have Level 2 and Level 3 fish and shellfish industry frameworks. Seafish and the Seafood Training Academy run short filleting and mongering courses, and the Master Fishmonger Standard developed by the Fishmongers' Company marks craft-level skill. A food hygiene qualification is strongly recommended, and the business must be registered with its local authority.

What knife does a fishmonger use?

There is no single fishmonger's knife. A long, narrow, flexible filleting knife of roughly 17–21cm runs along the backbone and skins fillets; a Japanese deba is a short, thick, single-bevel knife for breaking down whole fish; a yanagiba slices sashimi. A six-inch boning knife is the realistic all-rounder for a home kitchen. A nakiri or chukabocho cleaver is a vegetable knife and should not be used on fish bones.

How do I choose sustainable fish?

In the UK the reference is the Marine Conservation Society's Good Fish Guide, which rates seafood green for best choice, amber for acceptable with improvements needed, and red for fish to avoid. Ratings depend on the species, where it was caught or farmed, and how — so the same fish can be green from one fishery and red from another. The guide covers more than 600 ratings across around 130 species and is updated twice a year, so check the current rating rather than relying on memory.

Related guides

Sources

• Marine Conservation Society — The Good Fish Guide (rating system and update frequency)
• Seafish — Fishmonger training and fishmonger apprenticeships (apprenticeship levels and the March 2025 standard revision)
• Seafish Training — Master Fishmonger Standard (developed by the Fishmongers' Company)