Getting to Heathrow early Sunday morning

I would take the tube and try to get there by 7:00 a.m.

Getting there at seven for a flight that leaves 'something' before nine isn't a good idea -- simple math says that's less than two hours. The reason you've seen three-hour recommendations is that they're valid. Shoot for close to six. A cab is cheaper than a new batch of tickets.

The Piccadilly line is out - the first train from central London doesn't arrive until 7:50.

The N9 night bus is the public transport option; runs twice an hour and takes about an hour. Would only be practical if staying close to the route.

So the first train from Paddington to Heathrow is at 0625 on a Sunday in June. The journey time can be 15-25 minutes depending on what terminal you are going to. I fly in and out of London a lot and use Heathrow Express. I think getting there before 0700 for a 0900 departure is okay but really depends on what airline you are using. That is because if your flight is the only one that airline has at that time, the lines should not be long for bag drop. Most all have kiosk or online check-in but still need to check your docs and bag if you are checking one. Also, security line can vary at that time of day depending on the terminal location. Now that said, the train fair is 21 pounds each, so if you are 3 or more travelers, better to take a cab, which will run around 50-60 plus a tip. The good news is, going by cab is not a bad option on a Sunday because very little traffic. So for me, I would use the taxi in your situation if traveling with others.

Hope that helps.

or a car service - cheaper than a taxi, and the best car services are very good.

Agree with Nigel. For three of you a car service. For example www.justairports.com get good feedback..

Take Kathy's advice take the car service she suggested, and be there 3 hrs early, the tube is too hard with luggage, been in London for a week now and the tube is great with no luggage but to many stairs otherwise

Thank you! Sounds like the car service is the way to go!

Or stay at a hotel near the airport on Saturday night. That might take off some of the early morning travel stress on Sunday.

We always stay at a hotel near LHR the night before we catch a flight back to the US. That saves a lot of anxiety on early flights and the inexpensive Hoppa bus, that services all the LHR hotels, starts at 0430 to all terminals. There are many to choose from and we prefer a Travelodge for the bargain prices often found online. Two weeks ago we stayed at the Travelodge Heathrow Central for 29GBP/night. It was better than others we have used since it was in a neighborhood with pubs, markets, a pizza joint, and a Polish deli (YUM). At other hotels you are generally not near anything and have to use the hotel for meals. www.heathrow-airport-guide.co.uk.

I meant to add that you can enjoy London until you check out and have your hotel store luggage if you wish until early evening. You can take the Heathrow Express to Terminal 3, go outside opposite the American Airlines flight desks, catch the Hoppa bus, buy tickets from the driver, and have a pleasant evening. Not all buses go to all hotels but there is a schedule with bus numbers listing the hotels serviced at the pickup point, which is separate from the drop off point. We've also stayed at the Jury's Inn at LHR but prefer the bargain hotels like Travelodge and Premier Inn, both have websites and often have bargain rooms.