As one of the world's most expensive cities, London can be a cost-prohibitive vacation spot. If you're determined to see this historic city and enjoy the best it has to offer, there are ways to save money. Choosing the best time of year to visit can save you considerable cash in a variety of ways.

Flights

According to Cheapflights.com, the best time for bargains on flights to London is during September and October. Frommer's indicates that November 1 to December 12, and December 25 through March 14 are other times to get the best airfare bargains. Booking midweek flights saves money over flying at the beginning or end of the week. Avoid booking flights from June through the end of August when prices are higher, or during the two weeks before Christmas.

Accommodations

Hotel prices are cheaper in the off-season as well. Savings of up to 20 percent is possible on London accommodations during the months of November and January through March. Avoid visiting during mid-March through early June when prices begin to rise. Accommodations max out at their highest during mid-June through August. It is possible to save year-round by checking out special packages offered on specific hotel websites. Tickets to local events and attraction,s and occasional free meals often are included in package deals offered by hotels.

Sightseeing

Attraction and event prices typically stay the same year-round in London. However, there are options that allow you to save money on these. By purchasing the London Pass, visitors can save money, enjoy special deals and receive free admission to a variety of events and attractions. Passes may be bought for one, two, three or six days in adult and child versions. Prices vary according to the number of days for which you purchase the pass, and whether it is a child or adult pass. Winter discounts typically earn you 10 percent off the London Pass price. A London Pass with travel benefits is available to save you money on fares for trains, buses, subways and ferries.

Shopping

Spending the post-holiday period after the Christmas season in London is an excellent time to find bargains and save money shopping. After-Christmas sales that extend through the month of January provide huge savings on items such as clothing and shoes, china, crystal and flatware, linens and bedding, electronics and just about everything else. London merchants want to clear out their inventory to make room for new spring items that come at the end of January. Use your London Pass to gain additional discounts on certain items at participating stores.