¶1 — HomeStreet, Inc., sued the Department of Revenue (DOR) for a refund of business and occupation (B&O) taxes it alleged that it had overpaid. This case of first impression requires that we address whether RCW 82.04.4292 allows a lender to deduct, as “amounts derived from interest received,” service fees it earned on qualifying home loans it originated and then sold on the [830]*830secondary market under agreements that required loan servicing.1 If RCW 82.04.4292 allows the deductions for income from qualifying loans HomeStreet services but no longer owns, then it overpaid. We hold that when HomeStreet sold qualifying loans on the secondary market, it no longer received interest and was not entitled, under RCW 82-.04.4292, to a deduction from its income in calculating its B&O tax obligation. Accordingly, HomeStreet is not entitled to the requested refund, and we affirm the trial court’s summary judgment in favor of DOR.
Quinn-Brintnall, J.
[830]*830DISCUSSION
The Statutory Deduction
¶2 RCW 82.04.4292 allows those engaged in “banking, loan, security or other financial businesses” to deduct “amounts derived from interest received on” certain investments or loans when computing their B&O taxes. Specifically, the statute provides:
In computing tax there may be deducted from the measure of tax by those engaged in banking, loan, security or other financial businesses, amounts derived from interest received on investments or loans primarily secured by first mortgages or trust deeds on nontransient residential properties.
RCW 82.04.4292 (emphasis added).
[831]*831The Loans and Servicing Rights2
¶3 HomeStreet, Inc.,3 HomeStreet Capital Corporation,4 and HomeStreet Bank5 (collectively HomeStreet) originate, sell, securitize,6 and buy residential loans that are primarily “secured by first mortgages or deeds of trust on non-transient residential properties.” 2 Clerk’s Papers (CP) at 305.7
¶4 HomeStreet sells or securitizes most of the loans it originates on the secondary market.8 It sells the loans or securitized interests two ways:9 (1) “servicing released,” which means that HomeStreet sells the loan or security [832]*832without “retaining” the right to service the loan or security or (2) “servicing retained,” which means that HomeStreet sells the loan but “retains” the right to service the loan or security. 1 CP at 160. Purchasers may pay a “premium” for a servicing released sale. 10 3 CP at 543. HomeStreet also purchases the rights to service loans it does not originate.11
¶5 In return for servicing the service retained loans, HomeStreet is entitled to retain a portion of the borrowers’ interest payments, generally 0.35 to 0.40 percent of the interest portion of the payment; a set percentage of the remaining principal balance; or, in certain instances, “the difference between the interest rate on the loan and the interest rate on the security for which it serves as collateral, computed on the same principal amount and for the same period as the interest portion of the installment.” 4 CP at 617. It appears that HomeStreet takes its payment from the loans’ interest streams.12 In this dispute, Home-Street generally refers to the amounts it retains from the borrowers’ interest payments as “retained interest.” See 3 CP at 538.
¶6 HomeStreet’s servicing obligations and the amount of interest it may “retain” are set out in sales and servicing contracts between HomeStreet and the purchaser of the [833]*833loans, usually Fannie Mae (Federal National Mortgage Association).13 These contracts specifically state that the contractual agreement is between HomeStreet and the purchaser of the loans14 rather than between HomeStreet and the investors who are ultimately entitled to the principal and remaining interest or between HomeStreet and the borrowers.
¶7 The contracts HomeStreet provided DOR15 in discovery establish that HomeStreet is entitled to retain a portion of the interest it collects from the borrower and expressly state that this is compensation to HomeStreet for performing servicing obligations for the purchasers of the loans under these contracts. Most of the contracts, the related servicing guides, and other related documents and agreements also state that HomeStreet is selling “all of its right, title, and interest in the mortgage” and that these sales are “absolute.” 3 CP at 422.
¶8 In most instances, HomeStreet can sell or transfer the servicing contract and retain any fee or proceeds from [834]*834an approved sale or transfer, or, if the contract is terminated, it is entitled to some form of lump sum compensation. Although it does not appear that HomeStreet has ever exercised this right, the contracts also give HomeStreet the right to sell its servicing rights on the secondary market as stand-alone assets. The sales and servicing contracts, however, generally require the loan purchaser’s prior approval or consent.
¶9 In addition, HomeStreet can, and occasionally does, hire third parties as subservicers to perform some services required under the sales and servicing contracts. Generally, HomeStreet pays the third party servicers, or subservicers, a fixed fee not related to the size of the loan or the income stream generated by the loan.
¶10 Because HomeStreet retains a portion of the interest the borrower pays based on a percentage of interest or principal rather than receiving a flat fee for servicing the loan, HomeStreet’s income from the servicing right is contingent on several factors, such as the size of the loan, interest rate fluctuations, the length of the loan, whether the borrower prepays the loan, and whether the borrower defaults on the loan or the loan is foreclosed. Despite these variables, HomeStreet’s servicing and administrative costs are relatively fixed.
DOR Audit
¶11 In 1995, DOR’s audit division issued written instructions to HomeStreet, informing it that RCW 82.04.4292 did not apply to the amounts HomeStreet retained from the interest payments made on servicing retained loans. Despite this notice, HomeStreet continued to follow its reading of a previous DOR contrary determination, DOR Determination No. 92-403,16 and deducted the amounts received on [835]*835servicing retained loans from its gross income before calculating its tax obligation.
¶12 Following an audit, DOR assessed B&O tax on the income HomeStreet had retained from payments it collected on servicing retained loans for the period of January 1, 1997 to December 31, 2001. DOR also required Home-Street to start paying B&O tax on this income.17
Refund Action and Summary Judgment
¶13 HomeStreet subsequently reported and paid $20,224.72 in B&O taxes on “retained interest” received on servicing retained loans during January 2003. In March 2003, HomeStreet sued for a refund, arguing that the income generated by the “retained servicing rights” was deductible under ROW 82.04.4292 as an amount derived from interest received on qualifying loans. It brought this action under ROW 82.32.180. Relying on DOR Determination Nos. 92-39218 and 92-403 and questioning DOR Deter[836]*836mination No. 98-218,19 which overruled DOR Determination No. 92-392 in part, HomeStreet moved for summary judgment.
[837]*837¶14 It asserted three arguments in support of summary judgment. First, it argued that the amounts it received from the retained servicing rights were, in substance, interest because they were subject to interest rate fluctuations and other factors that affect income generated by a loan and because the servicing rights are imbedded in every residential mortgage loan. Second, it argued that according to DOR’s expert, Earl Baldwin, the retained servicing assets are “derivatives that are paid from interest on the underlying mortgage loan” and that, therefore, they qualify for the deduction under RCW 82.04.4292. Br. of Appellant at 15 (emphasis added) (citing 1 CP at 50). Finally, it argued that DOR’s refusal to allow the deduction undermined the legislative intent behind the deduction, which it characterized as attempting “ ‘to stimulate the residential housing market by making residential loans available to home buyers at lower cost through the vehicle of a B&O tax [deduction] on interest income received by home mortgage lenders.’ ” 1 CP at 189 (quoting Dep’t of Revenue v. Sec. Pac. Bank of Wash. Nat’l Ass’n, 109 Wn. App. 795, 804, 38 P.3d 354 (2002)). HomeStreet did not, however, cite support for its conclusion that DOR’s current interpretation would dampen home mortgage lending, nor did any of the documents it submitted in support of its summary judgment motion touch on this issue.
¶15 DOR opposed HomeStreet’s summary judgment motion, arguing that so called “retained interest” was a fee for services rather than interest and that the fact the payments were taken from or calculated with reference to the interest collected from the loans or investments did not establish that it was income “derived from interest received.” RCW 82.04.4292. DOR also asserted that Home-Street mischaracterized Baldwin’s statement regarding [838]*838whether servicing income is “derived” from interest and provided a declaration from Baldwin to that effect, and asserted that the legislative history of the deduction statute showed that the deduction was intended to apply only to “interest earned by the owner of the loan.” 4 CP at 761.
Trial Court’s Ruling
¶16 Noting that HomeStreet’s financing methods did not exist 35 years ago when the legislature enacted RCW 82.04.4292, the trial court denied HomeStreet’s motion for summary judgment, granted DOR summary judgment, and dismissed HomeStreet’s claim with prejudice.
¶17 HomeStreet appeals the denial of its motion for summary judgment and the order granting DOR summary judgment.
ANALYSIS
¶18 We review an order of summary judgment de novo, engaging “in the same inquiry as the trial court, [and] treating all facts and reasonable inferences from the facts in a light most favorable to the nonmoving party.” Enter. Leasing, Inc. v. City of Tacoma, 139 Wn.2d 546, 551, 988 P.2d 961 (1999) (citing Reid v. Pierce County, 136 Wn.2d 195, 201, 961 P.2d 333 (1998); Fell v. Spokane Transit Auth., 128 Wn.2d 618, 625, 911 P.2d 1319 (1996)). Summary judgment is appropriate only if the pleadings, affidavits, depositions, and admissions on file demonstrate the absence of any genuine issues of material fact, and the moving party is entitled to judgment as a matter of law. CR 56(c). ‘Where, as here, the parties do not dispute the material facts, [we] will affirm an order on summary judgment if the moving party is entitled to judgment as a matter of law.” Enter. Leasing, 139 Wn.2d at 551-52 (citing CR 56(c); Barnes v. McLendon, 128 Wn.2d 563, 569, 910 P.2d 469 (1996)).
Tax Deduction Standards
¶19 In this case, we interpret the language of a B&O deduction provision. Generally, taxation is the rule [839]*839and deductions or exemptions are exceptions to the rule. Budget Rent-A-Car of Wash.-Or., Inc. v. Dep’t of Revenue, 81 Wn.2d 171, 174, 500 P.2d 764 (1972) (citing Fibreboard Paper Prods. Corp. v. State, 66 Wn.2d 87, 401 P.2d 623 (1965)). Thus, we construe deductions to taxation narrowly and the party claiming the deduction has the burden of showing that it qualifies for the deduction. Budget Rent-A-Car, 81 Wn.2d at 174-75 (citing Group Health Coop. of Puget Sound, Inc. v. Tax Comm’n, 72 Wn.2d 422, 433 P.2d 201 (1967); All-State Constr. Co. v. Gordon, 70 Wn.2d 657, 425 P.2d 16 (1967); Yakima Fruit Growers Ass’n v. Henneford, 187 Wash. 252, 60 P.2d 62 (1936)).
¶20 If a deduction statute is ambiguous, we construe the statute “ ‘strictly, though fairly and in keeping with the ordinary meaning of [the] language, against the taxpayer.’ ” Simpson Inv. Co. v. Dep’t of Revenue, 141 Wn.2d 139, 150, 3 P.3d 741 (2000) (quoting Group Health, 72 Wn.2d at 429). Furthermore, when addressing tax classifications, we look to the substance rather than form of the business activity at issue to assess the proper classification. See Time Oil Co. v. State, 79 Wn.2d 143, 147, 483 P.2d 628 (1971) (citing Wash. Sav-Mor Oil Co. v. Tax Comm’n, 58 Wn.2d 518, 364 P.2d 440 (1961)).
General Rules op Statutory Interpretation
¶21 Statutory interpretation is a question of law, which we review de novo. Enter. Leasing, 139 Wn.2d at 552 (citing Millay v. Cam, 135 Wn.2d 193, 198, 955 P.2d 791 (1998)). When construing a statute, our goal is to give effect to legislative intent. Enter. Leasing, 139 Wn.2d at 552 (quoting State v. Sweet, 138 Wn.2d 466, 477-78, 980 P.2d 1223 (1999)). We first look to the plain language of the statute to determine its meaning. Enter. Leasing, 139 Wn.2d at 552 (quoting Sweet, 138 Wn.2d at 478). We review the disputed statutory language within the context of the statute as a whole, In re Sehome Park Care Ctr., Inc., 127 Wn.2d 774, 778, 903 P.2d 443 (1995) (citing Human Rights Comm’n v. Cheney Sch. Dist. No. 30, 97 Wn.2d 118, [840]*840121, 641 P.2d 163 (1982)), and avoid “[s]trained, unlikely or unrealistic” interpretations. Bour v. Johnson, 122 Wn.2d 829, 835, 864 P.2d 380 (1993).
¶22 Absent ambiguity or a statutory definition, we give the words in a statute their common and ordinary meaning. Garrison v. Wash. State Nursing Bd., 87 Wn.2d 195, 196, 550 P.2d 7 (1976). In determining the plain meaning of an undefined term, we may look to the dictionary to ascertain the common meaning of the term. Garrison, 87 Wn.2d at 196.
¶23 “ “Where a statute is susceptible to more than one meaning, it is ambiguous.’” Sehome Park Care Ctr., 127 Wn.2d at 778 (quoting Timberline Air Serv., Inc. v. Bell Helicopter-Textron, Inc., 125 Wn.2d 305, 312, 884 P.2d 920 (1994)). If a statute is ambiguous, we look to other evidence of legislative intent, such as legislative history. See Sehome Park Care Ctr., 127 Wn.2d at 778. In addition, we “accord great weight to the contemporaneous construction placed upon [the statute] by officials charged with its enforcement, especially where the Legislature has silently acquiesced in that construction over a long period.” Sehome Park Care Ctr., 127 Wn.2d at 780.
B&O Taxes and Deduction
¶24 The State imposes B&O tax on the privilege of doing business in this state. RCW 82.04.220. DOR computes B&O tax by classifying the taxpayer’s activity according to various statutory definitions and applying specific tax rates to the gross income of the business. See RCW 82.04.220. Businesses engaged in the business of providing financial and banking services are generally taxable under the “sendee and other activities” classification of the B&O tax. Former RCW 82.04.290 (2001); WAC 458-20-146.
¶25 For purposes of the B&O tax, the legislature has defined “gross income” as
the value proceeding or accruing by reason of the transaction of the business engaged in and includes gross proceeds of sales, [841]*841compensation for the rendition of services, gains realized from trading in stocks, bonds, or other evidences of indebtedness, interest, discount, rents, royalties, fees, commissions, dividends, and other emoluments however designated, all without any deduction on account of the cost of tangible property sold, the cost of materials used, labor costs, interest, discount, delivery costs, taxes, or any other expense whatsoever paid or accrued and without any deduction on account of losses.
RCW 82.04.080 (emphasis added); see also WAC 458-20-146.
¶26 RCW 82.04.4292 allows those engaged in “banking, loan, security or other financial businesses” to deduct “amounts derived from interest received on” certain investments or loans when computing their B&O taxes. The sole issue in this case is whether the trial court properly determined that there was no genuine issue of material fact as to whether the disputed amounts were “derived from interest received.” We agree with the trial court that there is not.
¶27 Factually, we note that HomeStreet’s chief financial officer, Debra Johnson, stated in a deposition that HomeStreet may record the income generated by the retained servicing rights contracts at issue as “servicing income” and that she was certain HomeStreet did not record this income as “retained interest.” 3 CP at 540-41. This suggests that the disputed income was derived from providing services rather than from interest received on investments or loans. More importantly, under the plain language of RCW 82.04.4292,20 the income in question is compensation for the servicing of the loans that is provided for in the contracts between HomeStreet and the secondary market purchasers, not a receipt by HomeStreet of interest paid by the borrower for the continued use of HomeStreet’s funds.
[842]*842¶28 HomeStreet argues that the statutory phrase “derived from, interest” includes any income taken from and related to the borrower’s interest payment and that the documents before the trial court on summary judgment clearly established that the income in question was withheld from and related to the borrower’s interest payments. It further asserts that Baldwin’s deposition establishes that the income is “ ‘paid from interest’ ” and is “ ‘embedded as a part of [interest],’ ” and that he “testified that HomeStreet’s retained interest (servicing) assets are derivatives that are paid from interest on the underlying mortgage loan.” Br. of Appellant at 15 (emphasis added) (citing CP at 50). It also asserts that because this income is sensitive to many of the same factors affecting direct interest income, such as the principal balance of the loan, interest rate fluctuations, and the duration of the loan, this income is similar to interest and that the legislature intended such income to be deductible under RCW 82.04.4292.
¶29 For its part, DOR contends that the amounts in question are fees for loan services provided, regardless of whether their ultimate source is the interest portion of the borrower’s payment. DOR argues that the phrase “derived from interest” “means the taxpayer must ‘receive’ interest” and that this portion of HomeStreet’s income is not from interest but rather from fees derived solely from its contractual servicing rights. See Br. of Resp’t at 13. It also asserts that, at least as to the loans it sells to Fannie Mae, HomeStreet sells “all its legal and beneficial interest in the secured loans”; that it is the “servicing contract that generates its income and not the secured loans”; and that HomeStreet’s only interest is contractual and this “is not secured by any lien against any real property of the borrower.” Br. of Appellant at 14.
¶30 Neither the term “interest” nor the phrase “derived from” are defined by the B&O tax statutes. Because these are undefined terms, we examine the plain meaning of these terms and may look to the dictionary to ascertain the common meaning. Garrison, 87 Wn.2d at 196.
[843]*843¶31 “Interest” is commonly defined as a “charge for the use or forbearance of money.” Sec. Sav. Soc’y v. Spokane County, 111 Wash. 35, 37, 189 P. 260 (1920); see also Clifford v. State, 78 Wn.2d 4, 6, 469 P.2d 549 (1970) (citing Merriam-Webster Third International Dictionary (1964)). “Derived” is defined as “formed or developed out of something else,” Webster’s Third International Dictionary 608 (1976), or “[r]eceived from specified source.” Black’s Law Dictionary 444 (6th ed. 1990). Thus, the plain language of the statute requires that the amount at issue be an amount “formed or developed” from a charge made for the use or forbearance of money.
¶32 The documents the parties submitted at summary judgment show that HomeStreet is allowed to keep or “retain” part of the interest stream generated by the loans in exchange for servicing the loans. In this respect, the income is, in the broadest sense, “derived from interest” because HomeStreet deducts it directly from the interest stream the loans generate. But HomeStreet’s argument ignores the fact that the only reason it is entitled to income is its contractual relationship with the purchaser of the loan for servicing the loans and that it is merely allowed to pay itself by “retaining” part of the contract purchaser’s interest payment in return.
¶33 When HomeStreet or any mortgage lender originates a mortgage loan, it creates a relationship between itself and the borrower by allowing the borrower to use its money in return for interest on its capital. This relationship falls squarely within the statutory tax deduction. But when HomeStreet sells the loan on the secondary market, it recovers the capital it invested and the borrower is no longer paying HomeStreet for using its money. And, in servicing retained sales, HomeStreet retains only the right to provide loan servicing for the purchaser of the loan and to be compensated for those services.21 Although Home-Street has clearly established that servicing rights are a [844]*844marketable asset, this asset is no longer directly related to the borrower’s use of HomeStreet’s capital, and, as evidenced by the servicing contracts between HomeStreet and the loan purchasers, the direct relationship between the borrower and HomeStreet is severed.
¶34 In fact, any servicer or subservicer, including those that never invested any capital in the serviced loans, could make the same argument HomeStreet relies on if the servicer or subservicer negotiated payment terms that required that the source of payment would be the borrower’s interest payment. HomeStreet’s approach is thus over-broad, unreasonable, and ignores the requirement that we construe tax deduction statutes narrowly. Budget Rent-A-Car, 81 Wn.2d at 174-75; see also Simpson Inv. Co., 141 Wn.2d at 150 (if the statute is ambiguous, this court must construe the statute “ ‘strictly, though fairly and in keeping with the ordinary meaning of [the] language, against the taxpayer’ ” (quoting Group Health, 72 Wn.2d at 429)).
¶35 We agree with the trial court that RCW 82.04.4292 allows HomeStreet to deduct interest income from qualifying home loans in computing its B&O tax but not income it earns from servicing loans it originated but then sold. We, therefore, affirm summary judgment for DOR.
Houghton, C.J., and Van Deren, J., concur.
Review granted at 163 Wn.2d 1022 (2008).