The BRC-Nielsen Shop Price Index (SPI) is a monthly measure of UK shop price inflation.

The SPI measures changes in the price of 500 of the most commonly bought items. The SPI demonstrates the extent to which retailers contribute to inflation through the pricing of commonly bought goods. The SPI is administered by Nielsen, who collate the data on behalf of the BRC. The BRC provide analysis and wider commentary on retail-specific and economy-wide inflation.