Lowes - 5% off.
For large - like whole house redo things - work up a material list, take it to the service desk at Lowes and have them submit it to corporate. Corporate will figure out the discounts. They -discounts- are substantial. The "business" card also has some sort of delivery discount - or at least it did pre-Covid. Then it was a flat $25 for anything. Bill payment is done by online payments, like everyone else we pay.
Home Depot discount comes in the form of a huge discount off an item when you first make a purchase - however- the discount is deferred until payment. If you forget you agreed to make the payment at a specified date, you pay full price and an interest charge that makes "Lou the knee cap breaker" blush. (DAMHIKT).
(The 12V Makita 3.5" trim saw and extra battery I picked up without letting my wife the bill payer know turned out to be very costly. )
Menards 2% off, access to special deals sent by mail, free tool for your birthday. The 2% comes in the form of a rebate - good only at Menards. The best thing about the Menards card is that the 2% credit is applied to sale prices and is good when Menards runs their 11% rebate on everything - even when the rebate makes the item free.
Menards payments are the easiest. They just "bill the bank". They payments are made via automatic bill payment with out bank. We just verify the amount that has been paid.