Recommended transfer time NRT-HND

Hi,
Is there any recommended transfer time for transfer from international flight to Narita and to a domestic from Haneda?

I know the bus takes about 60-90 minutes, plus I think at least 60 minutes prior to departure at Haneda, and maybe 60-90 minutes for immigration and customs at Narita until reaching the bus, etc. Plus possible delays of flight 0-60 minutes (or more).

Meaning 180 - 300 minutes (3-5 hours). Does it sound realistic?

When looking for flights one gave me about 3 hours of transfer time between NRT and HND...

plus I think at least 60 minutes prior to departure at Haneda,

Just 30 minutes will be fine, especially if you are already checked in (i.e., you already have your boarding pass).

The most critical part will be the transportation, so look carefully at the timetable for buses (on the bus company's website) or trains (on Hyperdia).

Thank you for the correction Firas.

It was quite long ago since I travelled domestic so. But I guess 30 minutes are needed since going through security and reaching the gate. When does it close, 10-15 minutes prior?

You have no recommendations on how much time I should put between flights?

The exact time required to make a connection depends on when exactly you are arriving, since the frequency of buses and trains varies throughout the day.

Oh yes you are right about that. Didnt think about the arrival.

Well, the plane is due to arrive in the morning, 8-10 AM, depending on season (daylight saving time makes it shift an hour). It will not be a night or late evening arrival.

Well, let's say 9am. Then you are about 95% certain to able to catch the limo bus leaving at 9:40, which arrives at Haneda around 11:15, so would be fine for a flight leaving around noon.

In any case, remember that if your flights are on the same ticket and you miss your connection for a reasonable reason such as a delayed flight or a delay in immigration/customs, the airline will put you on a later flight.

Wow. You mean it would be possible to pass immigraiton and customs in less than 40 minutes?

When I went to Japan several years ago I remember standing in probably an hour or more for immigration...

How would I prove to the airline that I was delayed such cases like long queues?

During peak, what would it be in case the next flight (or all) are full?