So when we're dealing with accounts receivable and bad debt expense, GAAP requires us to use an allowance account. Let's check that out. Like I said, GAAP requires the use of an allowance. This helps us conform with the matching principle. When we talked about the direct write-off method, it was not GAAP because it didn't follow the matching principle, okay? Bad debt expense, we talked about a little, but these are the losses that occur from extending credit to a customer but not getting paid, right? So we sold them something and said, okay, you can pay us later and then they never paid us later, well we have bad debt expense. Okay? And usually, when I write this, I'm going to shorthand it to BDE for bad debt expense. It's just a long thing to write and you can get away with BDE. Alright.
Just like allowance doubtful accounts, this is our big topic here and we're going to be short handing it as ADA for allowance for doubtful accounts. Well and by the way sometimes it's called allowance for uncollectible accounts something like that but this is the most common format, allowance doubtful accounts. So this account, it's a contra asset. Okay? We've talked about contra assets once before, but just so you remember, a contra asset, they're going to be paired with another account. And in this case, they're paired with accounts receivable. Okay? What a contra asset has is an opposite balance of the actual asset. So if you think about an asset, accounts receivable, it's going to have a debit balance. Right? That's how we're used to accounts receivable. Well, the allowance for doubtful accounts is going to have a credit balance, right? So the debit balance in accounts receivable and the credit balance in the allowance, well, that credit balance is going to lower the net balance, right? It's going to bring the debit a little lower because there are some credits over here. Alright?
We'll see more details about that, but remember a contra asset, they have an opposite balance than the regular account. So, if I was just hypothetically speaking, say, a contra liability, right? A contra liability, well, a liability has a credit balance, so a contra liability would have a debit balance. Okay?
So, the allowance, what we use it for is to estimate. The allowance helps us estimate the amount of bad debt in our accounts receivable, right? So if you think about it, we've got a certain amount of accounts receivable right now. Well, there's going to be in that batch of accounts receivable some amount of it that's bad debt, right? Well, the allowance helps us estimate that amount. So let's see how this happens and how we follow the matching principle here. Alright?
In year 1, we have credit sales, right? So in year 1, notice we have credit sales, so we take an entry like debiting accounts receivable and crediting revenue. Right? Because this is a credit sale. We're going to be paid sometime in the future. But we're also going to have another entry at this point to deal with the bad debt expense. Okay? So we're going to estimate from all these accounts receivable. We made all these credit sales and we have all these accounts receivable. We're going to estimate how much of it is not collectible. Okay? So that's what we're going to make this second entry. Notice in year 1, we're making an entry for bad debt expense. So bad debt expense is going to be debited and we're going to credit the allowance for doubtful accounts. So notice we credited allowance for doubtful accounts, right? So that was a contra asset, right? This is a credit balance that's related to our accounts receivable account, Okay? So notice what happened. In year 1, we took our revenue and we took a related expense. Okay? So that's the matching principle. It all happened in year 1.
Now notice what happens in year 2. In year 2, we finally decide, hey, we're not going to be able to collect some certain amount of that money. Well, that's fine. We already took the expense. We're not going to take an expense at this point. So notice that the expense, the bad debt expense, it got put into the allowance for doubtful accounts, right? So whenever we want to write off an account in the allowance method, we're going to debit the allowance because it's coming out of the allowance. So this will lower the balance in the allowance and we're going to credit accounts receivable, right, to get the account receivable off of our books. Think about it. We had this account receivable on our books and now we're finally deciding that we're not going to collect it. Well, we have to credit it to get rid of it and we already took the bad debt expense related to that account in year 1. So now in year 2, we just have to decrease the allowance because this is us finally finding that bad debt that we expected in year 1. Okay?
So we would decrease the allowance and our accounts receivable in those amounts that we decided were uncollectible and those numbers would all have to be given to you. They would have to tell you, oh, $1,000 was deemed uncollectible in year 2 or, you know, all these things have there's going to be a lot that has to be given to you in these questions. So when we calculate our allowance, we're going to deal with 2 methods that we're going to talk about in a separate video. The first one is the percentage of sales method and with this method, the bad debt expense is estimated as, guess what, a percentage of credit sales. So we're going to have so many credit sales in this year, say we had $1,000,000 worth of credit sales and we'll say 3% of those are uncollectible, right? So we'll be able to find out how much is uncollectible, well, 3% of that million. Okay?
So notice in this method, what we calculate is the bad debt expense and then we can find the ending balance in the allowance using that information. Now, don't worry too much about the details. There's going to be much more detailed explanations of this. I'm just showing you the 2 methods here. The second one, aging of receivables method. Well, in this method, we're going to see how old every receivable is, right? We would expect a receivable that's only been in our account for 2 weeks. Well, we could probably still collect that, but maybe a receivable that's been in the account for 2 years, well, you know maybe that money's not coming in. So what we do is we use a schedule based on the age and then we estimate what the ending balance in the allowance should be and this is based on the age of each receivable. Right? So the older the receivable, the more likely that we won't collect it. So in this method, notice we calculate the ending balance.
So the percentage of sales method, we calculate the bad debt expense, the aging of receivables, we calculate the ending balance in the allowance, okay? And then we back into our bad debt expense. Cool. Let's pause real quick. This has been quite a hefty topic and then we'll do this example below, alright? Let's do that.