Cheapism is editorially independent. We may earn a commission if you buy through links on our site.

The best way to get a good deal is to shop around, right? But running from store to store can gobble up time and gas. That's where price matching comes in: Top retailers from Best Buy to Walmart have pledged to match competitors' prices, so consumers can get the best deals from around town with only one stop. Target recently expanded its policy to include a total of 29 online retailers. Problem is, these guarantees are far from straightforward. Cheapism.com examined eight retailers' price-match policies and found scads of rules and exclusions. Here are seven things every bargain shopper should know about price matching.

Only a few stores match online prices.

Some retailers match local competitors' websites, but many policies exclude online pricing. Target is one of only a few stores that have agreed to match prices at select online retailers, even if there is no corresponding store nearby. The price-match guarantees at Best Buy and Walmart also extend to specified online competitors, including Amazon. Shoppers can scan items at these stores with the Amazon app on their phones to find out if they can get a better price without ordering online. One catch with online price matching: It does not extend to marketplace items listed by third-party sellers.

'Local' has different definitions.

Most policies require the competitor to be a local store, but what qualifies as "local" may be up for debate. Retailers tend to leave it to store managers familiar with the area to decide what lies within the same market or within a "reasonable distance." Best Buy sets a specific radius of 25 miles, while JC Penney stores in Alaska will match the prices of any similar store in the entire state.

A competitor's print ad is the best evidence.

Each retailer has its own rules about what qualifies as proof that another store is offering a lower price. A print ad with the competitor's price clearly displayed is the only verification accepted everywhere. A photocopy, picture, or mobile version of the ad may not work. Walmart does not officially require any form of proof (an employee can call the other store to verify a claim), but shoppers suggest bringing in an ad to minimize the wait and hassle.

The items must be identical.

The item you're buying and the item offered for less at the other store must be identical in every way -- brand, style, color, condition, size, weight, and, perhaps trickiest of all, model number. Retailers such as Home Depot, Lowe's, and Best Buy sell many high-priced appliances and electronics with store-specific model numbers, which rules them out for price matching.

Certain sales and promotions are excluded.

Retailers will not match another store's going-out-of-business or clearance-sale prices. Limited-time promotions, rebates, and offers of free products or gift cards with purchase are also unlikely to be eligible. One exception: Walmart matches buy-one-get-one-free offers as long as the ad lists the price of the item. In general, an ad must specify a price in order for a retailer to match it; a percentage or dollar amount off is not enough.

Many retailers offer price adjustments even after purchase.

Shoppers may be able to request a price match for something they've already purchased, depending how much time has passed. Some policies include a specific time frame for price adjustment -- Target now allows 14 days, for example -- but often the decision is left to a store manager. Some stores offer a price adjustment only if they've dropped their own price, not if a customer spots a better deal from a competitor.

Policies are subject to employee interpretation.

This can cut both ways. At JC Penney, Cheapism found that managers seem to have a lot of authority to match competitors' prices, so it may not hurt to stretch the limits of the store's price-matching policy. At Walmart, on the other hand, shoppers complain that employees deviate from corporate policy in denying customer requests. In either case, it helps to know the fine print going in. Cheapism's comparison of stores that price match highlights important features of each policy and offers some store-specific money-saving tips.