Mortgage revenue outperformance relative to the mortgage market at about 24 points is expected to benefit 2024 total revenue growth by about 4.5%, more than offsetting the almost 3 percentage points of negative revenue impact from the mortgage market decline. As a result, the expected about 9.5% increase in total mortgage revenue was a positive 1.5% impact on overall revenue growth. Non-mortgage organic revenue growth is expected to be about 8.5% on a constant currency basis and is driving about 7% of the growth in overall revenue. As Mark referenced earlier, the growth is within our long-term framework and is broad-based across all three BUs and again, the strongest performance in Workforce Solutions. The BVS acquisition completed last August is expected to contribute about 2 percentage points of revenue growth to 2024.
Slide 16 provides an adjusted EPS walk, detailing the drivers of the expected 9.5% increase to the midpoint of our 2024 adjusted EPS guidance of $7.35 per share. Revenue growth of 8.6% at our 2023 EBITDA margins of 32.2% will deliver 12.5% growth in adjusted EPS. EBITDA margins in 2024 are expected to be about 33.3%, expanding about 110 basis points from 2023. The margin expansion delivers about 6 points of adjusted EPS growth. The expansion in margins is driven by the factors: organic constant dollar revenue growth in 2024 at about 8.5% is within our long-term financial framework. Consistent with that framework, we will generate about 50 basis points of margin expansion from high variable margins on our revenue growth. The cost reduction actions we executed in 2023 as well as actions related to the charge we announced this quarter will generate about $90 million in incremental spending reductions in 2024, of which about $60 million is expense savings in 2024 or about 100 basis points in EBITDA margin expansion.
The actions we took in 2023 will generate an additional $65 million in spending reductions in 2024 on top of the $210 million of spending reductions in 2023. The cost action we announced this quarter will generate an additional $25 million in spending reductions in 2024. In 2024, cost savings we will generate from decommissioning of North American infrastructure in the second half of ’23 will exceed the redundant system and migration costs we are incurring, generating about 30 basis points of margin benefit. Partially offsetting the about 180 basis points of margin expansion I referenced above, is principally higher variable compensation expense from the normalization of incentive and sales comp in 2024 that were at low levels in 2023 due to the substantial impact of the weak mortgage market on our performance.
In 2024, our planning assumes we return to target levels of performance. As we look beyond 2024, the cost benefits of completing our cloud migration as well as accelerating high variable profit revenue growth are expected to drive significant improvement in EBITDA margins. In 2024, adjusted EBITDA should increase to about $1.9 billion, up 12.5% from 2023. Depreciation and amortization is expected to increase by about $60 million in 2024, which will negatively impact adjusted EPS by about 5%. D&A is increasing in 2024 as we accelerate putting cloud-native systems into production. The P&L line items below operating income, principally interest and other expense and tax expense, are expected to negatively impact adjusted EPS by about 4 percentage points.
The increase in interest expense reflects the impact of higher interest rates and the increased debt from our BBS acquisition. Our estimated tax rate of about 26.7% is 50 basis points higher than the 26.2% in 2023, principally from higher foreign earnings. Slide 17 provides the specifics on our 2020 full year guidance that Mark discussed in detail. This slide includes additional detail on expected BU adjusted EBITDA margins as well as guidance on specific P&L line items. EWS EBITDA margins in 2024 at 52% are expected to be up from the 51% delivered in 2023, given strong non-mortgage revenue growth from new products, record growth, penetration and pricing, partially offset by the normalization of incentive comp. USIS EBITDA margins are expected to be about 34.5%, about flat with 2023.
USIS is benefiting from revenue growth and 2023 cost actions. However, in the first half ‘24, USIS will have redundant systems costs as well as costs related to customer migrations prior to completion of migration of the consumer credit systems to Data Fabric. USIS is also being impacted by the normalization of incentive comp. International EBITDA margins at about 28% are expected to expand versus the 26.5% delivered in 2023, driven principally by revenue growth and good performance on 2023 cost actions. Corporate expense, excluding depreciation and amortization is increasing in 2024 relative to 2023 due to the increases in incentive and equity compensation from the lower levels incurred in 2023 that I referenced earlier. Corporate functions such as finance, legal, HR, corporate technology and others are managing costs consistent with the cost actions we have taken in 2023.
As Mark indicated, capital spending should be about $475 million in 2024, down over $100 million from 2023. We believe that our guidance is centered at the midpoint of both our revenue and adjusted EPS guidance ranges. With EBITDA increasing to about $1.9 billion and capital spending declining to $475 million, we expect to deliver over 50% growth in free cash flow in 2024 versus the $518 million we delivered in 2023. At this level of EBITDA and free cash flow, our EBITDA leverage should decline from the current levels of about 3.2x to 2.5x as we complete 2024. We believe these levels of leverage are nicely within the levels required for our current BBB, Baa2 credit ratings. As we achieve these levels, we will have significant flexibility to begin to return cash to shareholders through dividend increases and share repurchases as well as continue to do bolt-on acquisitions.
Slide 18 provides our guidance for 1Q ’24. Revenue at the midpoint of guidance is expected to be about $1.385 billion, up 6.4% from 1Q ’23. Constant currency growth is expected to be about 7.8%, with organic constant currency growth of about 4.7%. Non-mortgage revenue constant currency growth will be about 9.5%. Mortgage revenue should grow about 1% despite overall USIS and twin inquiry transactions being down about 26%. Business unit performance in the first quarter are expected to be as described below: Workforce Solutions revenue is expected to grow about 2% year-to-year. EWS mortgage revenue will be down about 15% and is expected to outperform underlying twin inquiries by about 11%. This mortgage outperformance is below the 18% we saw in 4Q as we lap the substantial growth in mortgage 36 volumes that occurred in the first quarter of ’23.
As we have discussed in the past, EWS long-term mortgage outperformance is expected to be about 11% to 13%, consistent with twin records, product and price levers that will drive overall Workforce Solutions’ long-term revenue growth to 13% to 15%. Non-mortgage revenue should grow about 9% with Verifier non-mortgage revenue up 15%. Employer revenue will be down about 4% in the quarter due to the decline in ERC revenue that was referenced earlier. Excluding the significant decline in ERC revenue, total Workforce Solutions non-mortgage revenue will be up over 11% with employer up about 4.5%. EBITDA margins are expected to be about 50.5%, about flat year-to-year and down a little over 50 basis points sequentially, principally due to negative seasonal mix from higher employer services revenue in 1Q.
USIS revenue is expected to be up about 9% year-to-year. Mortgage revenue will be up over 25%. USIS mortgage revenue is expected to outperform USIS credit inquiries by over 50% in the quarter. In the first quarter, we are benefiting from the significant price increases from a vendor that we discussed earlier as well as Equifax new product growth and pricing benefits. This level of outperformance versus the mortgage credit inquiries is expected to decline to under 30% as we move through 2024. USIS non-mortgage revenue is expected to be up about 3%. Non-mortgage will again be led by strong growth in commercial and identity and fraud and continued growth in FI consumer and FMS. EBITDA margins are expected to be about 32%, flat versus the first quarter of ’23 and down about 300 basis points sequentially.
In the first half of 2024, USIS is also incurring incremental costs from customer migrations to the Consumer Credit Exchange on Data Fabric. This is impacting 1Q ’24 margins in addition to the seasonal decline in non-mortgage revenue and normalization of incentive compensation we referenced earlier. International constant currency revenue is expected to be up about 18%, representing about 4% organic constant currency growth from continued strong growth in Latam and Europe as well as mid-single-digit growth in Canada, offset by the decline in Asia Pacific discussed earlier. EBITDA margins are expected to be about 24%, up about 50 basis points versus 1Q ’23, but down sequentially due to seasonally lower revenue in Canada and the UK, CRA and incentive costs.
1Q ’24 Equifax EBITDA margins are expected to be about 29%, about flat with the first quarter of ’23. As we discussed last year, corporate expense is much higher in the first quarter each year. The bulk of the expense related to our equity plans occurs in the first quarter and is reflected in corporate. Excluding the timing of equity compensation expense and the normalization of variable compensation in 2024, EBITDA margins would be over 32%. Corporate expenses will decrease meaningfully sequentially in 2Q ’24 as the equity compensation was principally reflected in 1Q ’24. We are expecting adjusted EPS in 1Q ’24 to be $1.33 to $1.43 per share compared to 1Q ’23 adjusted EPS of $1.43 per share. Now I’d like to turn it over to Mark.
