Before you start

Passport for a prepaid SIM
Address card and residence permit for postpaid
A Hungarian bank account for direct debit on most contracts
Landlord permission for any installation work

Step-by-step

1
Buy a registered prepaid SIM on arrival
All three operators sell prepaid packs in shops, malls and at the airport, registered against your passport. Data allowances are reasonable and it covers the weeks before the address card exists.
In personWho: YouDay 1
2
Move to postpaid once the address card is in hand
Postpaid plans want the address card, a residence permit and usually a Hungarian bank account. They are cheaper per gigabyte and bundle handset financing over 12 or 24 months.
In personWho: You
3
Ask what is wired into the building before choosing a provider
Budapest buildings are served by whichever operators have installed equipment there. In the inner districts that is usually two or three, but an old block can be limited to one. The building's answer, not the operator's coverage map, determines your real choice.
In personWho: You
4
Check for existing cabling in old Pest buildings
The nineteenth-century apartment blocks that make inner Pest attractive frequently have awkward cabling routes and courtyard risers. Where the existing wiring ends can cap your speed regardless of the plan. Ask the landlord what connection the previous tenant had and at what speed.
In personWho: You
5
Expect roaming and EU calls to be included
Hungarian plans include EU roaming under the EU rules, which matters more here than in most places because Vienna, Bratislava and Zagreb are all short trips.
Mobile appWho: You
6
Port your number rather than starting fresh
Hungary operates number portability and the process is quick. Do not cancel the old contract before the port completes.
In personWho: You

Documents you’ll need

Passport for prepaid registration
Address card and residence permit for postpaid
Hungarian bank details for direct debit
Landlord permission for installation

Things most newcomers don’t know

The address card gates the phone contract too, which is the third time it appears in a Budapest checklist.

Prepaid works on a passport. Postpaid, home internet and most bundles want the lakcímkártya. So the same landlord signature that determines your bank account and your health cover also determines whether you can get a normal phone plan. Budapest newcomers who understand this in week one sequence the flat hunt around the address registration question and save themselves two months.

Source: community-reported

Inner Pest's beautiful old buildings are frequently the worst-connected ones.

The courtyard apartment blocks of Districts V, VI and VII date from the 1870s to the 1900s. Retrofitting fibre through their risers is awkward and expensive, and many are served by older cable rather than fibre to the flat. A newly renovated apartment in an old block can still be behind a copper segment. Ask what the previous tenant's actual measured speed was, not what the building is advertised as supporting.

Source: community-reported

Prepaid SIMs are registered, so the anonymous option does not exist.

Hungarian operators register prepaid SIMs against identity documents. A passport is enough, so this is no obstacle on arrival, but it does mean there is no anonymous option — a point worth knowing for anyone planning around one, and reassuring for anyone worried about being unable to get a working number before their permit arrives.

Source: NMHH

Hungary sits at a crossroads that makes EU roaming unusually valuable.

Vienna is two and a half hours by train, Bratislava under three, and Zagreb, Belgrade, Krakow and Ljubljana are all weekend-range. EU roaming rules mean a Hungarian plan works at domestic rates across the EU — but Serbia is not in the EU, so a trip to Belgrade is the one that generates an unexpected bill. Check the non-EU rates before that particular journey.

Source: community-reported